Ultralow-temperature device dedicated to soft X-ray magnetic circular dichroism experiments
A new ultralow-temperature setup dedicated to soft X-ray absorption spectroscopy and X-ray magnetic circular dichroism (XMCD) experiments is described. Two experiments, performed on the DEIMOS beamline (SOLEIL synchrotron), demonstrate the outstanding performance of this new platform in terms of the lowest achievable temperature under X-ray irradiation (T = 220   mK), the precision in controlling the temperature during measurements as well as the speed of the cooling-down and warming-up procedures. Moreover, owing to the new design of the setup, the eddy-current power is strongly reduced, allowing fast scanning of the ma...
Source: Journal of Synchrotron Radiation - October 19, 2018 Category: Physics Authors: Kappler, J.-P. Otero, E. Li, W. Joly, L. Schmerber, G. Muller, B. Scheurer, F. Leduc, F. Gobaut, B. Poggini, L. Serrano, G. Choueikani, F. Lhotel, E. Cornia, A. Sessoli, R. Mannini, M. Arrio, M.-A. Sainctavit, P. Ohresser, P. Tags: ultralow-temperature soft X-rays XMCD magnetism research papers Source Type: research

Flexible sample cell for real-time GISAXS, GIWAXS and XRR: design and construction
Since the properties of functional materials are highly dependent on their specific structure, and since the structural changes, for example during crystallization, induced by coating and annealing processes are significant, the study of structure and its formation is of interest for fundamental and applied science. However, structure analysis is often limited to ex situ determination of final states due to the lack of specialized sample cells that enable real-time investigations. The lack of such cells is mainly due to their fairly complex design and geometrical restrictions defined by the beamline setups. To overcome thi...
Source: Journal of Synchrotron Radiation - October 8, 2018 Category: Physics Authors: Berlinghof, M. B ä r, C. Haas, D. Bertram, F. Langner, S. Osvet, A. Chumakov, A. Will, J. Schindler, T. Zech, T. Brabec, C.J. Unruh, T. Tags: in situ GIWAXS GISAXS XRR thin film research papers Source Type: research

A comparison of parametric and integrative approaches for X-ray fluorescence analysis applied   to a Stroke model
Synchrotron X-ray fluorescence imaging enables visualization and quantification of microscopic distributions of elements. This versatile technique has matured to the point where it is used in a wide range of research fields. The method can be used to quantitate the levels of different elements in the image on a pixel-by-pixel basis. Two approaches to X-ray fluorescence image analysis are commonly used, namely, (i) integrative analysis, or window binning, which simply sums the numbers of all photons detected within a specific energy region of interest; and (ii) parametric analysis, or fitting, in which emission spectra are ...
Source: Journal of Synchrotron Radiation - October 8, 2018 Category: Physics Authors: Crawford, A.M. Sylvain, N.J. Hou, H. Hackett, M.J. Pushie, M.J. Pickering, I.J. George, G.N. Kelly, M.E. Tags: M-BLANK X-ray fluorescence strokes window binning Xpress 3 electronics research papers Source Type: research

Rigorous calculations and synchrotron radiation measurements of diffraction efficiencies for tender X-ray lamellar gratings: conical versus classical diffraction
In this study it will be shown that scalar calculations are not appropriate for this purpose, while newly introduced rigorous calculations based on the boundary integral equation method, implemented in the PCGrate ® code, can provide predictions that are in agreement with observed diffraction efficiencies. The agreement is achieved by modelling the exact surface profile. This applies for both the conical diffraction configuration and for the classical in-plane configuration, in which a significantly lower efficiency was obtained. Even though the profile of the presented grating was not perfect, but significantly distor...
Source: Journal of Synchrotron Radiation - October 8, 2018 Category: Physics Authors: Goray, L. Jark, W. Eichert, D. Tags: diffraction gratings diffraction theory computational electromagnetic methods X-ray optics research papers Source Type: research

Rocking curve and spatial coherence properties of   a   long X-ray compound refractive lens
Semi-analytical theory of a long set of X-ray compound refractive lenses (CRLs) based on recurrence relations is developed further. The geometrical aperture, angular divergence of incident radiation and source size were accurately taken into account. Using this theory it is possible to calculate the width of the rocking curve of a long (40.7   cm) Be CRL which coincides with experimental data obtained earlier. By this approach the transverse coherence length for the X-ray beam after passing a set of CRLs of arbitrary complexity has been estimated. It is shown that at the focus this coherence length is equal to a diffract...
Source: Journal of Synchrotron Radiation - October 5, 2018 Category: Physics Authors: Kohn, V.G. Tags: X-ray focusing compound refractive lens rocking curve computer simulations recurrent relations coherence research papers Source Type: research

Implications of X-ray beam profiles on qualitative and quantitative synchrotron micro-focus X-ray fluorescence microscopy
Synchrotron radiation X-ray fluorescence microscopy is frequently used to investigate the spatial distribution of elements within a wide range of samples. Interrogation of heterogeneous samples that contain large concentration ranges has the potential to produce image artefacts due to the profile of the X-ray beam. The presence of these artefacts and the distribution of flux within the beam profile can significantly affect qualitative and quantitative analyses. Two distinct correction methods have been generated by referencing the beam profile itself or by employing an adaptive-thresholding procedure. Both methods signific...
Source: Journal of Synchrotron Radiation - September 28, 2018 Category: Physics Authors: Morrell, A.P. Mosselmans, J.F.W. Geraki, K. Ignatyev, K. Castillo-Michel, H. Monksfield, P. Warfield, A.T. Febbraio, M. Roberts, H.M. Addison, O. Martin, R.A. Tags: X-ray fluorescence microscopy X-ray fluorescence spectroscopy artefacts research papers Source Type: research

Experimental feasibility of dual-energy computed tomography based on the Thomson scattering X-ray source
Unlike large-scale and expensive synchrotron radiation facilities, the Thomson scattering X-ray source can provide quasi-monochromatic, energy-tunable and high-brightness X-ray pulses with a small footprint and moderate cost, making it an excellent candidate for dual-energy and multi-energy imaging at laboratories and hospitals. Here, the first feasibility study on dual-energy computed tomography (CT) based on this type of light source is reported, and the effective atomic number and electron-density distribution of a standard phantom consisting of polytetrafluoroethylene, water and aluminium is derived. The experiment was...
Source: Journal of Synchrotron Radiation - September 28, 2018 Category: Physics Authors: Chi, Z. Du, Y. Yan, L. Wang, D. Zhang, H. Huang, W. Tang, C. Tags: dual-energy imaging Thomson scattering X-ray source effective atomic number electron density research papers Source Type: research

Elaborations on M ö ssbauer rotor experiments with synchrotron radiation and with usual resonant sources
A comparative analysis of M ö ssbauer experiments in a rotating system between a recent application using synchrotron radiation [Friedman et al. (2016). Eur. Phys. Lett. 114, 50010; Friedman et al. (2017). J. Synchrotron Rad. 24, 661 – 666] and usual sources of resonant radiation is carried out. The principal methodological difference between these experiments can be related to the fact that in the former set of experiments the source of the resonant radiation rests in a laboratory frame whereas for the latter set of experiments the source is attached to a rotating system. It is concluded that the utilization of...
Source: Journal of Synchrotron Radiation - September 28, 2018 Category: Physics Authors: Kholmetskii, A.L. Yarman, T. Yarman, O. Arik, M. Tags: M ö ssbauer effect rotating system synchrotron radiation research papers Source Type: research

The HEPS project
The High Energy Photon Source (HEPS), a 6   GeV green-field diffraction-limited storage ring light source, will be built in Beijing, China. The HEPS design has been evolving for about ten years, and is now mostly finished and ready for construction. The storage ring is based on a modified hybrid seven-bend achromat (7BA) design, where bending magnets with reverse bending angles and longitudinal gradients are adopted to reach an ultralow natural emittance of 34.2   pm with a circumference of 1360.4   m. The central slice of the dipole in the middle of the modified hybrid 7BA, with flexible magnetic field, is used as t...
Source: Journal of Synchrotron Radiation - September 28, 2018 Category: Physics Authors: Jiao, Y. Xu, G. Cui, X.-H. Duan, Z. Guo, Y.-Y. He, P. Ji, D.-H. Li, J.-Y. Li, X.-Y. Meng, C. Peng, Y.-M. Tian, S.-K. Wang, J.-Q. Wang, N. Wei, Y.-Y. Xu, H.-S. Yan, F. Yu, C.-H. Zhao, Y.-L. Qin, Q. Tags: High Energy Photon Source (HEPS) diffraction-limited storage ring modified hybrid seven-bend achromat feature articles Source Type: research

Simultaneous X-ray radioscopy/tomography and energy-dispersive diffraction applied to liquid aluminium alloy foams
High-speed X-ray imaging in two dimensions (radioscopy) and three dimensions (tomography) is combined with fast X-ray diffraction in a new experimental setup at the synchrotron radiation source BESSY   II. It allows for in situ studies of time-dependent phenomena in complex systems. As a first application, the foaming process of an aluminium alloy was studied in three different experiments. Radioscopy, optical expansion measurements and diffraction were used to correlate the change of foam morphology to the various phases formed during heating of an AlMg15Cu10 alloy to 620 ° C in the first experiment. Radioscopy was ...
Source: Journal of Synchrotron Radiation - September 26, 2018 Category: Physics Authors: Jim é nez, C. Paeplow, M. Kamm, P.H. Neu, T.R. Klaus, M. Wagener, G. Banhart, J. Genzel, C. Garc í a-Moreno, F. Tags: tomography radioscopy diffraction simultaneous metal foam research papers Source Type: research

Time-resolved pair distribution function analysis of   disordered materials on beamlines BL04B2 and BL08W at SPring-8
A dedicated apparatus has been developed for studying structural changes in amorphous and disordered crystalline materials substantially in real time. The apparatus, which can be set up on beamlines BL04B2 and BL08W at SPring-8, mainly consists of a large two-dimensional flat-panel detector and high-energy X-rays, enabling total scattering measurements to be carried out for time-resolved pair distribution function (PDF) analysis in the temperature range from room temperature to 873   K at pressures of up to 20   bar. For successful time-resolved analysis, a newly developed program was used that can monitor and process ...
Source: Journal of Synchrotron Radiation - September 26, 2018 Category: Physics Authors: Ohara, K. Tominaka, S. Yamada, H. Takahashi, M. Yamaguchi, H. Utsuno, F. Umeki, T. Yao, A. Nakada, K. Takemoto, M. Hiroi, S. Tsuji, N. Wakihara, T. Tags: time-resolved measurements pair distribution functions beamlines disordered materials crystallization research papers Source Type: research

Low-cost disposable high-pressure setup for in situ X-ray experiments
A low-cost, flexible and fast method to create disposable sample cells suitable for in situ catalytic or material synthesis studies based on standard quartz capillaries, heat-shrinkable tubing and standard Swagelok components is described. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - September 20, 2018 Category: Physics Authors: Houlleberghs, M. Martens, J.A. Breynaert, E. Tags: in situ XRD/XAS high-pressure flexible sample cell design in situ X-ray experiments hardware laboratory notes Source Type: research

Responsive alignment for X-ray tomography beamlines
X-ray computed tomography (CT) is an imaging technique intended to obtain the internal structure and three-dimensional representation of a sample. In general, parallel-beam CT reconstruction algorithms require a precise angular alignment and knowledge of the exact axis of rotation position. Highly brilliant X-ray sources with ever-increasing data-acquisition rates demand optimized alignment techniques to avoid compromising in situ data analysis. This paper presents a method to automatically align the angular orientation and linear position of the rotation axis in a tomography setup, correlating image features from differen...
Source: Journal of Synchrotron Radiation - September 20, 2018 Category: Physics Authors: Jos é Querino de Vasconcelos, G. Xavier Miqueles, E. Schubert Ruiz Costa, G. Tags: X-ray tomography tomography setup automatic alignment linear misalignment angular misalignment research papers Source Type: research

Track analysis of a synchrotron X-ray photoelectric nanoradiator by in situ fluorescence imaging of reactive oxygen species: comparative study of gold and iron oxide nanoparticles
The emission of fluorescent X-rays and low-energy electrons by mid-/high-Z nanoparticles upon irradiation with either X-ray photons or high-energy ion beams is referred to as the nanoradiator effect (NRE). A track analysis of NRE was performed using reactive oxygen species (ROS) gels, to which macrophages containing gold nanoparticles (AuNPs) were attached, together with single-cell irradiation of the intracellular nanoparticles from a microbeam of synchrotron X-rays, and the range and distribution of ^\bulletOH and O2^{ \bullet - } produced were compared with those of the Fe-nanoradiator by magnetite nanoparticles (FeONP,...
Source: Journal of Synchrotron Radiation - September 20, 2018 Category: Physics Authors: Jeon, J.-K. Kim, J.-K. Tags: X-ray photoelectric nanoradiator ROS-oxidant fluorescence gel dosimetry track analysis gold nanoparticles iron oxide nanoparticle research papers Source Type: research

Ultrahigh-vacuum organic molecular-beam deposition system for in situ growth and characterization
A compact ultrahigh-vacuum molecular-beam deposition system has been developed for the in situ synthesis of organic thin films and multilayers. The system incorporates all the features (heater, thickness monitor, evaporators) necessary for controlled organic thin-film growth. It can be used independently, or it can be docked to the in situ growth system and transferred to other instruments of the PGM beamline, thus allowing extensive film preparation and characterization. A manipulator dedicated to specimen preparation and organic-film deposition with temperature control between 200   K and ∼ 800   K has been devel...
Source: Journal of Synchrotron Radiation - September 20, 2018 Category: Physics Authors: Annese, E. Santos, J.E. dos Rodrigues, G.L.M.P. Rocha, A.S. Moraes, H.R. de Cezar, J.C. Tags: organic molecular deposition in situ preparation research papers Source Type: research

Depth-dependent atomic valence determination by synchrotron techniques
The properties of many materials can be strongly affected by the atomic valence of the contained individual elements, which may vary at surfaces and other interfaces. These variations can have a critical impact on material performance in applications. A non-destructive method for the determination of layer-by-layer atomic valence as a function of material thickness is presented for La0.7Sr0.3MnO3 (LSMO) thin films. The method utilizes a combination of bulk- and surface-sensitive X-ray absorption spectroscopy (XAS) detection modes; here, the modes are fluorescence yield and surface-sensitive total electron yield. The weight...
Source: Journal of Synchrotron Radiation - September 20, 2018 Category: Physics Authors: Trappen, R. Zhou, J. Tra, V.T. Huang, C.-Y. Dong, S. Chu, Y.-H. Holcomb, M.B. Tags: X-ray absorption valence manganites thin films Hamiltonian calculations research papers Source Type: research

Synchrotron Methods for Energy Materials. X-ray Studies on Electrochemical Systems. By Artur Braun. DeGruyter, 2017. Pp. xxviii + 474. Price EUR 79.95, USD 91.99, GBP 65.99, paperback, ISBN 978-3-11-043750-8.
(Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - August 28, 2018 Category: Physics Authors: Imai, H. Tags: book review synchrotron methods electrochemical systems book reviews Source Type: research

A new synchrotron rapid-scanning X-ray fluorescence (SRS-XRF) imaging station at SSRL beamline 6-2
This paper describes a new large-range rapid-scan X-ray fluorescence (XRF) imaging station at beamline 6-2 at the Stanford Synchrotron Radiation Lightsource at SLAC National Accelerator Laboratory. This station uses a continuous rapid-scan system with a scan range of 1000 × 600   mm and a load capacity of up to 25   kg, capable of 25 – 100   µ m resolution elemental XRF mapping and X-ray absorption spectroscopy (XAS) of a wide range of objects. XRF is measured using a four-element Hitachi Vortex ME4 silicon drift detector coupled to a Quantum Detectors Xspress3 multi-channel analyzer system. A custo...
Source: Journal of Synchrotron Radiation - August 28, 2018 Category: Physics Authors: Edwards, N.P. Webb, S.M. Krest, C.M. van Campen, D. Manning, P.L. Wogelius, R.A. Bergmann, U. Tags: synchrotron X-ray fossils fluorescence imaging beamlines Source Type: research

A comparison of absorption and phase contrast for X-ray imaging of biological cells
X-ray imaging allows biological cells to be examined at a higher resolution than possible with visible light and without some of the preparation difficulties associated with electron microscopy of thick samples. The most used and developed technique is absorption contrast imaging in the water window which exploits the contrast between carbon and oxygen at an energy of around 500   eV. A variety of phase contrast techniques are also being developed. In general these operate at a higher energy, enabling thicker cells to be examined and, in some cases, can be combined with X-ray fluorescence imaging to locate specific metal...
Source: Journal of Synchrotron Radiation - August 27, 2018 Category: Physics Authors: Nave, C. Tags: X-ray imaging biological cells dose and fluence requirements research papers Source Type: research

Commissioning and first-year operational results of   the MAX   IV 3   GeV ring
The MAX   IV 3   GeV electron storage ring in Lund, Sweden, is the first of a new generation of light sources to make use of the multibend-achromat lattice (MBA) to achieve ultralow emitance and hence ultrahigh brightness and transverse coherence. The conceptual basis of the MAX   IV 3   GeV ring project combines a robust lattice design with a number of innovative engineering choices: compact, multifunctional magnet blocks, narrow low-conductance NEG-coated copper vacuum chambers and a 100   MHz radio-frequency system with passively operated third-harmonic cavities for bunch lengthening. In this paper, commission...
Source: Journal of Synchrotron Radiation - August 27, 2018 Category: Physics Authors: Tavares, P.F. Al-Dmour, E. Andersson, Å . Cullinan, F. Jensen, B.N. Olsson, D. Olsson, D.K. Sj ö str ö m, M. Tarawneh, H. Thorin, S. Vorozhtsov, A. Tags: storage ring synchrotron light source multibend achromat MAX IV feature articles Source Type: research

Soft X-ray refractive index by reconciling total electron yield with specular reflection: experimental determination of the optical constants of graphite
The complex refractive index of many materials is poorly known in the soft X-ray range across absorption edges. This is due to saturation effects that occur there in total-electron-yield and fluorescence-yield spectroscopy and that are strongest at resonance energies. Aiming to obtain reliable optical constants, a procedure that reconciles electron-yield measurements and reflection spectroscopy by correcting these saturation effects is presented. The procedure takes into account the energy- and polarization-dependence of the photon penetration depth as well as the creation efficiency for secondary electrons and their escap...
Source: Journal of Synchrotron Radiation - August 24, 2018 Category: Physics Authors: Jansing, C. Wahab, H. Timmers, H. Gaupp, A. Mertins, H.-C. Tags: soft X-rays optical constants X-ray spectroscopy graphite birefringence research papers Source Type: research

Effects of energy spread on brightness and coherence of undulator sources
The (spectral) brightness for partially transverse coherent sources such as synchrotron radiation and free-electron laser sources can be defined as the maximum of the Wigner distribution. Then, the brightness includes information on both coherence and wavefront characteristics of the radiation field. For undulator sources, it is customary to approximate the single-electron electric field at resonance with a Gaussian beam, leading to great simplifications. Attempts to account for the modified spatial and angular profile of the undulator radiation in the presence of detuning due to energy spread, currently build on the simpl...
Source: Journal of Synchrotron Radiation - August 24, 2018 Category: Physics Authors: Geloni, G. Serkez, S. Khubbutdinov, R. Kocharyan, V. Saldin, E. Tags: synchrotron radiation brightness Wigner distribution undulator radiation energy spread research papers Source Type: research

Improved charge transfer multiplet method to simulate M- and L-edge X-ray absorption spectra of metal-centered excited states
Charge transfer multiplet (CTM) theory is a computationally undemanding and highly mature method for simulating the soft X-ray spectra of first-row transition metal complexes. However, CTM theory has seldom been applied to the simulation of excited-state spectra. In this article, the CTM4XAS software package is extended to simulate M2,3- and L2,3-edge spectra for the excited states of first-row transition metals and also interpret CTM eigenfunctions in terms of Russell – Saunders term symbols. These new programs are used to reinterpret the recently reported excited-state M2,3-edge difference spectra of photogenerated...
Source: Journal of Synchrotron Radiation - August 23, 2018 Category: Physics Authors: Zhang, K. Girolami, G.S. Vura-Weis, J. Tags: multiplet simulations electronic structure valence excited states X-ray spectroscopy computer programs Source Type: research

High-speed raster-scanning synchrotron serial microcrystallography with a high-precision piezo-scanner
The Frontier Microfocus Macromolecular Crystallography (FMX) beamline at the National Synchrotron Light Source II with its 1   µ m beam size and photon flux of 3 × 1012 photons   s − 1 at a photon energy of 12.66   keV has reached unprecedented dose rates for a structural biology beamline. The high dose rate presents a great advantage for serial microcrystallography in cutting measurement time from hours to minutes. To provide the instrumentation basis for such measurements at the full flux of the FMX beamline, a high-speed, high-precision goniometer based on a unique XYZ piezo positioner has been d...
Source: Journal of Synchrotron Radiation - August 23, 2018 Category: Physics Authors: Gao, Y. Xu, W. Shi, W. Soares, A. Jakoncic, J. Myers, S. Martins, B. Skinner, J. Liu, Q. Bernstein, H. McSweeney, S. Nazaretski, E. Fuchs, M.R. Tags: macromolecular crystallography nano-positioning serial crystallography raster-scanning high-precision goniometer research papers Source Type: research

Combining synchrotron light with laser technology in catalysis research
High-energy surface X-ray diffraction (HESXRD) provides surface structural information with high temporal resolution, facilitating the understanding of the surface dynamics and structure of the active phase of catalytic surfaces. The surface structure detected during the reaction is sensitive to the composition of the gas phase close to the catalyst surface, and the catalytic activity of the sample itself may affect the surface structure, which in turn may complicate the assignment of the active phase. For this reason, planar laser-induced fluorescence (PLIF) and HESXRD have been combined during the oxidation of CO over a ...
Source: Journal of Synchrotron Radiation - August 23, 2018 Category: Physics Authors: Blomberg, S. Zetterberg, J. Gustafson, J. Zhou, J. Shipilin, M. Pfaff, S. Hejral, U. Carlsson, P.-A. Gutowski, O. Bertram, F. Lundgren, E. Tags: high-energy surface X-ray diffraction (HESXRD) planar laser-induced fluorescence (PLIF) CO oxidation Pd(100) research papers Source Type: research

Classification of ab   initio models of proteins restored from small-angle X-ray scattering
In structure analyses of proteins in solution by using small-angle X-ray scattering (SAXS), the molecular models are restored by using ab   initio molecular modeling algorithms. There can be variation among restored models owing to the loss of phase information in the scattering profiles, averaging with regard to the orientation of proteins against the direction of the incident X-ray beam, and also conformational fluctuations. In many cases, a representative molecular model is obtained by averaging models restored in a number of ab   initio calculations, which possibly provide nonrealistic models inconsistent wit...
Source: Journal of Synchrotron Radiation - August 22, 2018 Category: Physics Authors: Oide, M. Sekiguchi, Y. Fukuda, A. Okajima, K. Oroguchi, T. Nakasako, M. Tags: small-angle X-ray scattering ab   initio molecular modeling multivariate analysis low-resolution structure protein structure research papers Source Type: research

Development of an experimental set-up for low-temperature spectroscopic studies of matrix-isolated molecules and molecular ices using synchrotron radiation
An experimental set-up for studying photophysics and photochemistry of molecules in an inert gas medium (matrix-isolated) and in the ice phase at low temperatures has been developed and commissioned at the Photophysics beamline, Indus-1 synchrotron radiation source. This end-station uses an in-house-developed closed-cycle cryostat for achieving cryo-temperatures ( ∼ 10   K). Synchrotron radiation from the Photophysics beamline is used as the source of UV – VUV photons and the system is equipped with a Fourier transform infrared spectrometer for characterization of the molecular species formed at low temperature...
Source: Journal of Synchrotron Radiation - August 22, 2018 Category: Physics Authors: Singh, P.J. Sundararajan, K. Shastri, A. Kumar, V. Das, A.K. Kush, P.K. Raja Sekhar, B.N. Tags: synchrotron radiation matrix isolation low temperature VUV spectroscopy molecular ices FTIR research papers Source Type: research

SciPhon: a data analysis software for nuclear resonant inelastic X-ray scattering with applications to Fe, Kr, Sn, Eu and Dy
The synchrotron radiation technique of nuclear resonant inelastic X-ray scattering (NRIXS), also known as nuclear resonance vibrational spectroscopy or nuclear inelastic scattering, provides a wealth of information on the vibrational properties of solids. It has found applications in studies of lattice dynamics and elasticity, superconductivity, heme biochemistry, seismology, isotope geochemistry and many other fields. It involves probing the vibrational modes of solids by using the nuclear resonance of M ö ssbauer isotopes such as 57Fe, 83Kr, 119Sn, 151Eu and 161Dy. After data reduction, it provides the partial phono...
Source: Journal of Synchrotron Radiation - August 21, 2018 Category: Physics Authors: Dauphas, N. Hu, M.Y. Baker, E.M. Hu, J. Tissot, F.L.H. Alp, E.E. Roskosz, M. Zhao, J. Bi, W. Liu, J. Lin, J.-F. Nie, N.X. Heard, A. Tags: NRIXS GUI software data reduction Mossbauer lattice dynamics computer programs Source Type: research

Using refractive lenses to provide a variable spot size for Kirkpatrick – Baez mirrors
For many X-ray microprobe experiments it is desirable to be able to vary the beam size: using large beams for survey scans and a small beam for the final measurements. Beryllium refractive lenses were found to be a simple and controllable method for enlarging the focus in a Kirkpatrick – Baez-based microprobe. They can provide variable spot size, can be quickly inserted or removed and do not move the beam center on the sample. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - August 21, 2018 Category: Physics Authors: Heald, S.M. Dufresne, E.M. Tags: X-ray microprobe Kirkpatrick – Baez mirror refractive lenses short communications Source Type: research

On-chip THz spectrometer for bunch compression fingerprinting at fourth-generation light sources
The layout of an integrated millimetre-scale on-chip THz spectrometer is presented and its peformance demonstrated. The device is based on eight Schottky-diode detectors which are combined with narrowband THz antennas, thereby enabling the simultaneous detection of eight frequencies in the THz range on one chip. The size of the active detector area matches the focal spot size of superradiant THz radiation utilized in bunch compression monitors of modern linear electron accelerators. The 3   dB bandwidth of the on-chip Schottky-diode detectors is less than 10% of the center frequency and allows pulse-resolved detection at...
Source: Journal of Synchrotron Radiation - August 21, 2018 Category: Physics Authors: Laabs, M. Neumann, N. Green, B. Awari, N. Deinert, J. Kovalev, S. Plettemeier, D. Gensch, M. Tags: THz on chip spectrometer bunch compression X-ray free-electron laser short communications Source Type: research

Tomosaic: efficient acquisition and reconstruction of teravoxel tomography data using limited-size synchrotron X-ray beams
X-rays offer high penetration with the potential for tomography of centimetre-sized specimens, but synchrotron beamlines often provide illumination that is only millimetres wide. Here an approach is demonstrated termed Tomosaic for tomographic imaging of large samples that extend beyond the illumination field of view of an X-ray imaging system. This includes software modules for image stitching and calibration, while making use of existing modules available in other packages for alignment and reconstruction. The approach is compatible with conventional beamline hardware, while providing a dose-efficient method of data acqu...
Source: Journal of Synchrotron Radiation - August 21, 2018 Category: Physics Authors: Vescovi, R. Du, M. Andrade, V. de Scullin, W. G ü rsoy, D. Jacobsen, C. Tags: X-ray tomography image alignment image reconstruction parallelized computing research papers Source Type: research

APS Data Management System
As the capabilities of modern X-ray detectors and acquisition technologies increase, so do the data rates and volumes produced at synchrotron beamlines. This brings into focus a number of challenges related to managing data at such facilities, including data transfer, near real-time data processing, automated processing pipelines, data storage, handling metadata and remote user access to data. The Advanced Photon Source Data Management System software is designed to help beamlines deal with these issues. This paper presents the system architecture and describes its components and functionality; the system's current usage i...
Source: Journal of Synchrotron Radiation - August 15, 2018 Category: Physics Authors: Veseli, S. Schwarz, N. Schmitz, C. Tags: computer software data management data processing computer programs Source Type: research

High-efficiency coherence-preserving harmonic rejection with crystal optics
This work reports a harmonic-rejection scheme based on the combination of Si(111) monochromator and Si(220) harmonic-rejection crystal optics. This approach is of importance to a wide range of X-ray applications in all three major branches of modern X-ray science (scattering, spectroscopy, imaging) based at major facilities, and especially relevant to the capabilities offered by the new diffraction-limited storage rings. It was demonstrated both theoretically and experimentally that, when used with a synchrotron undulator source over a broad range of X-ray energies of interest, the harmonic-rejection crystals transmit the ...
Source: Journal of Synchrotron Radiation - August 14, 2018 Category: Physics Authors: Zhang, F. Allen, A.J. Levine, L.E. Long, G.G. Kuzmenko, I. Ilavsky, J. Tags: harmonic rejection monochromator coherent X-ray scattering SAXS XAFS research papers Source Type: research

Ultrafast X-ray imaging of laser – metal additive manufacturing processes
The high-speed synchrotron X-ray imaging technique was synchronized with a custom-built laser-melting setup to capture the dynamics of laser powder-bed fusion processes in situ. Various significant phenomena, including vapor-depression and melt-pool dynamics and powder-spatter ejection, were captured with high spatial and temporal resolution. Imaging frame rates of up to 10   MHz were used to capture the rapid changes in these highly dynamic phenomena. At the same time, relatively slow frame rates were employed to capture large-scale changes during the process. This experimental platform will be vital in the further unde...
Source: Journal of Synchrotron Radiation - August 14, 2018 Category: Physics Authors: Parab, N.D. Zhao, C. Cunningham, R. Escano, L.I. Fezzaa, K. Everhart, W. Rollett, A.D. Chen, L. Sun, T. Tags: X-ray imaging laser powder-bed fusion particle ejection melt pools vapor depressions additive manufacturing research papers Source Type: research

One way only to synchrotron light sources upgrade?
The last decade has seen a renaissance of machine-physics studies and technological advancements that aim to upgrade at least 15 synchrotron light sources worldwide to diffraction-limited storage rings. This is expected to improve the average spectral brightness and transversally coherent fraction of photons by several orders of magnitude in the soft- and hard-X-ray wavelength range, at the expense of pulse durations longer than ∼ 80   ps FWHM. This paper discusses the compatibility of schemes for the generation of sub-picosecond photon-pulse durations in synchrotron light sources with standard multi-bunch user opera...
Source: Journal of Synchrotron Radiation - August 14, 2018 Category: Physics Authors: Di Mitri, S. Tags: synchrotron radiation free-electron laser short pulse diffraction limit storage ring electron-optics design research papers Source Type: research

Advantages of breast cancer visualization and characterization using synchrotron radiation phase-contrast tomography
The aim of this study was to highlight the advantages that propagation-based phase-contrast computed tomography (PB-CT) with synchrotron radiation can provide in breast cancer diagnostics. For the first time, a fresh and intact mastectomy sample from a 60 year old patient was scanned on the IMBL beamline at the Australian Synchrotron in PB-CT mode and reconstructed. The clinical picture was described and characterized by an experienced breast radiologist, who underlined the advantages of providing diagnosis on a PB-CT volume rather than conventional two-dimensional modalities. Subsequently, the image quality was assessed b...
Source: Journal of Synchrotron Radiation - August 13, 2018 Category: Physics Authors: Pacil è , S. Baran, P. Dullin, C. Dimmock, M. Lockie, D. Missbach-Guntner, J. Quiney, H. McCormack, M. Mayo, S. Thompson, D. Nesterets, Y. Hall, C. Pavlov, K. Prodanovic, Z. Tonutti, M. Accardo, A. Fox, J. Tavakoli Taba, S. Lewis, S. Brennan, P. Hauserma Tags: phase-contrast breast CT synchrotron radiation breast cancer imaging research papers Source Type: research

In situ study of sigma phase formation in Cr – Co – Ni ternary alloys at 800 ° C using the long duration experiment facility at Diamond Light Source
The new long duration experiment facility on beamline I11 at Diamond Light Source has been used to study the kinetics of sigma phase formation in three Cr – Co – Ni alloys. Diffraction data acquired during in situ exposure at 800 ° C for 50   d showed progressive increases in the sigma fraction. This was accompanied by changes in the proportions of the other phases, which differed markedly between the alloys studied. These results demonstrate the capabilities of the long duration facility for the study of metallurgical phenomena over periods of months to years, a capability not previously available at a s...
Source: Journal of Synchrotron Radiation - August 13, 2018 Category: Physics Authors: Connor, L.D. Mignanelli, P.M. Christofidou, K. Jones, N.G. Baker, A.R. Tang, C.C. Gu é rin, S. Stone, H. Tags: sigma TCP (topologically close-packed phase) synchrotron X-ray powder diffraction SEM (scanning electron microscopy) ternary alloys metallurgial phenomena research papers Source Type: research

An iterative image reconstruction algorithm combined with forward and backward diffusion filtering for in-line X-ray phase-contrast computed tomography
In this study, an iterative reconstruction algorithm for IL-PCCT was proposed by combining the simultaneous algebraic reconstruction technique (SART) with eight-neighbour forward and backward (FAB8) diffusion filtering, and the reconstruction was performed using the Shepp – Logan phantom simulation and a real synchrotron IL-PCCT experiment. The results showed that the proposed algorithm was able to produce high-quality computed tomography images from few-view projections while improving the convergence rate of the computed tomography reconstruction, indicating that the proposed algorithm is an effective method of dos...
Source: Journal of Synchrotron Radiation - August 9, 2018 Category: Physics Authors: Zhao, Y. Sun, M. Ji, D. Cong, C. Lv, W. Zhao, Q. Qin, L. Jian, J. Chen, X. Hu, C. Tags: in-line X-ray phase-contrast computed tomography simultaneous algebraic reconstruction technique forward and backward diffusion filtering few-view projections research papers Source Type: research

Characterization of Pd/Y multilayers with B4C barrier layers using GIXR and X-ray standing wave enhanced HAXPES
Pd/Y multilayers are high-reflectance mirrors designed to work in the 7.5 – 11   nm wavelength range. Samples, prepared by magnetron sputtering, are deposited with or without B4C barrier layers located at the interfaces of the Pd and Y layers to reduce interdiffusion, which is expected from calculating the mixing enthalpy of Pd and Y. Grazing-incident X-ray reflectometry is used to characterize these multilayers. B4C barrier layers are found to be effective in reducing Pd – Y interdiffusion. Details of the composition of the multilayers are revealed by hard X-ray photoemission spectroscopy with X-ray standing...
Source: Journal of Synchrotron Radiation - August 9, 2018 Category: Physics Authors: Wu, M.-Y. Huang, Q.-S. Le Guen, K. Ilakovac, V. Li, B.-X. Wang, Z.-S. Giglia, A. Rueff, J.-P. Jonnard, P. Tags: Pd/Y nanometric multilayers hard X-ray photoemission spectroscopy X-ray standing waves research papers Source Type: research

PETRA IV: the ultralow-emittance source project at DESY
The PETRA IV project aims at upgrading the present synchrotron radiation source PETRA   III at DESY into an ultralow-emittance source. Being diffraction limited up to X-rays of about 10   keV, PETRA   IV will be ideal for three-dimensional X-ray microscopy of biological, chemical and physical processes under realistic conditions at length scales from atomic dimensions to millimetres and time scales down to the sub-nanosecond regime. In this way, it will enable groundbreaking studies in many fields of science and industry, such as health, energy, earth and environment, mobility and information technology. The science ...
Source: Journal of Synchrotron Radiation - August 9, 2018 Category: Physics Authors: Schroer, C.G. Agapov, I. Brefeld, W. Brinkmann, R. Chae, Y.-C. Chao, H.-C. Eriksson, M. Keil, J. Nuel Gavald à , X. R ö hlsberger, R. Seeck, O.H. Sprung, M. Tischer, M. Wanzenberg, R. Weckert, E. Tags: PETRA IV ultralow-emittance source diffraction-limited storage ring feature articles Source Type: research

XUV double-pulses with femtosecond to 650   ps separation from a multilayer-mirror-based split-and-delay unit at FLASH
Extreme ultraviolet (XUV) and X-ray free-electron lasers enable new scientific opportunities. Their ultra-intense coherent femtosecond pulses give unprecedented access to the structure of undepositable nanoscale objects and to transient states of highly excited matter. In order to probe the ultrafast complex light-induced dynamics on the relevant time scales, the multi-purpose end-station CAMP at the free-electron laser FLASH has been complemented by the novel multilayer-mirror-based split-and-delay unit DESC (DElay Stage for CAMP) for time-resolved experiments. XUV double-pulses with delays adjustable from zero femtosecon...
Source: Journal of Synchrotron Radiation - August 3, 2018 Category: Physics Authors: Sauppe, M. Rompotis, D. Erk, B. Bari, S. Bischoff, T. Boll, R. Bomme, C. Bostedt, C. D ö rner, S. D ü sterer, S. Feigl, T. Fl ü ckiger, L. Gorkhover, T. Kolatzki, K. Langbehn, B. Monserud, N. M ü ller, E. M ü ller J.P. Passow, C. Ramm, D. Rolles, D. Tags: split-and-delay unit free-electron laser pump – probe multilayer mirror temporal and spatial overlap beamlines Source Type: research

Time-resolved in situ tomography for the analysis of evolving metal-foam granulates
An experimental setup has been developed that allows for capturing up to 25 tomograms   s − 1 using the white X-ray beam at the experimental station EDDI of BESSY II, Berlin, Germany. The key points are the use of a newly developed, precise and fast rotation stage, a very efficient scintillator and a fast CMOS camera. As a first application, the foaming of aluminium alloy granules at 923   K was investigated in situ. Formation and growth of bubbles in the liquid material were observed and found to be influenced by the limited thermal conductivity in the bulk granules. Changes that took place between two tomograph...
Source: Journal of Synchrotron Radiation - August 3, 2018 Category: Physics Authors: Garc í a-Moreno, F. Kamm, P.H. Neu, T.R. Banhart, J. Tags: time-resolved tomography in situ tomography dynamic processes metal-foam granulates short communications Source Type: research

Switching of the harmonic order in free-electron lasers by controlling the density modulation of an electron bunch
It was demonstrated that harmonic order in free-electron laser (FEL) oscillations could be switched by adjusting the dispersive gap of the optical klystron ETLOK-III in the storage ring NIJI-IV. The effective gains for the fundamental and third-harmonic FEL oscillations were evaluated and it was confirmed that the FEL oscillated at the order of the harmonic with the higher effective gain. The ratio between the effective gain for the fundamental and that for the third harmonic was controlled by the dispersive gap. It was also demonstrated that a spectral measurement of the FEL-based Compton scattering X-ray beam was effecti...
Source: Journal of Synchrotron Radiation - August 3, 2018 Category: Physics Authors: Sei, N. Ogawa, H. Jia, Q. Tags: free-electron lasers higher harmonic oscillation optical klystron effective gains inverse Compton scattering X-rays research papers Source Type: research

The scanning four-bounce monochromator for beamline I20 at the Diamond Light Source
A description of the technical and design details of a scanning four-bounce crystal monochromator that has recently been commissioned for the Versatile X-ray Absorption Spectroscopy (XAS) beamline at Diamond Light Source is presented. This device consists of two independent rotary axes of unique design which are synchronized using a multiple read-head encoder system. This monochromator is shown to be capable of maintaining the flux throughput of the Bragg axes without the need of any external feedback mechanism from 4 to 20   keV. The monochromator is currently equipped with cryogenically cooled crystals with the upstrea...
Source: Journal of Synchrotron Radiation - August 2, 2018 Category: Physics Authors: Hayama, S. Duller, G. Sutter, J.P. Amboage, M. Boada, R. Freeman, A. Keenan, L. Nutter, B. Cahill, L. Leicester, P. Kemp, B. Rubies, N. Diaz-Moreno, S. Tags: X-ray absorption spectroscopy beamline monochromator optics beamlines Source Type: research

High-power-load DCLM monochromator for a computed tomography program at BMIT at energies of 25 – 150 keV
The research program at the biomedical imaging facility requires a high-flux hard-X-ray monochromator that can also provide a wide beam. A wide energy range is needed for standard radiography, phase-contrast imaging, K-edge subtraction imaging and monochromatic beam therapy modalities. The double-crystal Laue monochromator, developed for the BioMedical Imaging and Therapy facility, is optimized for the imaging of medium- and large-scale samples at high energies with the resolution reaching 4   µ m. A pair of 2   mm-thick Si(111) bent Laue-type crystals were used in fixed-exit beam mode with a 16   mm vertical b...
Source: Journal of Synchrotron Radiation - August 2, 2018 Category: Physics Authors: Wysokinski, T.W. Renier, M. Suortti, P. Belev, G. Rousset, L. Adam, M. Miller, D. Huber, N. Chapman, L.D. Tags: DCLM hard X-ray monochromator X-ray imaging. Laue – Laue monochromator beamlines Source Type: research

CAMP@FLASH: an end-station for imaging, electron- and ion-spectroscopy, and pump – probe experiments at the FLASH free-electron laser
The non-monochromatic beamline BL1 at the FLASH free-electron laser facility at DESY was upgraded with new transport and focusing optics, and a new permanent end-station, CAMP, was installed. This multi-purpose instrument is optimized for electron- and ion-spectroscopy, imaging and pump – probe experiments at free-electron lasers. It can be equipped with various electron- and ion-spectrometers, along with large-area single-photon-counting pnCCD X-ray detectors, thus enabling a wide range of experiments from atomic, molecular, and cluster physics to material and energy science, chemistry and biology. Here, an overview...
Source: Journal of Synchrotron Radiation - August 2, 2018 Category: Physics Authors: Erk, B. M ü ller, J.P. Bomme, C. Boll, R. Brenner, G. Chapman, H.N. Correa, J. D ü sterer, S. Dziarzhytski, S. Eisebitt, S. Graafsma, H. Grunewald, S. Gumprecht, L. Hartmann, R. Hauser, G. Keitel, B. von Korff Schmising, C. Kuhlmann, M. Manschwetus, B. Tags: free-electron laser soft X-rays pump – probe electron-ion-spectrometers imaging detector micro-focus Kirkpatrick Baez mirrors beamlines Source Type: research

HAXPES beamline PES-BL14 at the Indus-2 synchrotron radiation source
The Hard X-ray Photo-Electron Spectroscopy (HAXPES) beamline (PES-BL14), installed at the 1.5   T bending-magnet port at the Indian synchrotron (Indus-2), is now available to users. The beamline can be used for X-ray photo-emission electron spectroscopy measurements on solid samples. The PES beamline has an excitation energy range from 3   keV to 15   keV for increased bulk sensitivity. An in-house-developed double-crystal monochromator [Si   (111)] and a platinum-coated X-ray mirror are used for the beam monochromatization and manipulation, respectively. This beamline is equipped with a high-energy (up to 15   k...
Source: Journal of Synchrotron Radiation - August 2, 2018 Category: Physics Authors: Jagannath Goutam, U.K. Sharma, R.K. Singh, J. Dutta, K. Sule, U.S. R., P. Gadkari, S.C. Tags: photo-electron spectroscopy HAXPES beamline Indus-2 bending magnet beamlines Source Type: research

Realization of a scanning soft X-ray microscope for magnetic imaging under high magnetic fields
For the purpose of imaging element- and shell-specific magnetic distributions under high magnetic fields, a scanning soft X-ray microscope has been developed at beamline BL25SU, SPring-8, Japan. The scanning X-ray microscope utilizes total electron yield detection of absorbed circularly polarized soft X-rays in order to observe magnetic domains through the X-ray magnetic circular dichroism effect. Crucially, this system is equipped with an 8   T superconducting magnet. The performance and features of the present system are demonstrated by magnetic domain observations of the fractured surface of a Nd14.0Fe79.7Cu0.1B6.2 si...
Source: Journal of Synchrotron Radiation - August 2, 2018 Category: Physics Authors: Kotani, Y. Senba, Y. Toyoki, K. Billington, D. Okazaki, H. Yasui, A. Ueno, W. Ohashi, H. Hirosawa, S. Shiratsuchi, Y. Nakamura, T. Tags: X-ray microscopy magnetic domains X-ray magnetic circular dichroism Nd – Fe B research papers Source Type: research

Sub-microsecond-resolved multi-speckle X-ray photon correlation spectroscopy with a pixel array detector
Small-angle X-ray photon correlation spectroscopy (XPCS) measurements spanning delay times from 826   ns to 52.8   s were performed using a photon-counting pixel array detector with a dynamic range of 0 – 3 (2   bits). Fine resolution and a wide dynamic range of time scales was achieved by combining two modes of operation of the detector: (i) continuous mode, where data acquisition and data readout are performed in parallel with a frame acquisition time of 19.36   µ s, and (ii) burst mode, where 12 frames are acquired with frame integration times of either 2.56   µ s   frame − 1 or 826 ...
Source: Journal of Synchrotron Radiation - August 2, 2018 Category: Physics Authors: Zhang, Q. Dufresne, E.M. Narayanan, S. Maj, P. Koziol, A. Szczygiel, R. Grybos, P. Sutton, M. Sandy, A.R. Tags: pixel array detector (PAD) X-ray photon correlation spectroscopy (XPCS) multi-speckle XPCS research papers Source Type: research

Characterization and on-line adjustment of the sagittal-bent Laue crystal profile
The sagittal-bent Laue monochromator can provide an ideal way to focus high-energy X-ray beams. However, the anticlastic curvature induced by sagittal bending has a great influence on the crystal performance. Thus, characterizing the bent-crystal shape is very important for predicting the performance of the bent-crystal monochromator. In this paper the crystal profile is measured by off-line optical metrology and on-line X-ray experiments. The off-line results showed that the bent-crystal surface could be well fitted to a saddle surface apart from a redundant cubic term which was related to the different couples applied on...
Source: Journal of Synchrotron Radiation - August 2, 2018 Category: Physics Authors: Dong, W. Cai, Q. Yang, F. Liu, X. Yang, J. Diao, Q. Liu, P. Zhang, X. Hu, L. Tags: sagittal-bent Laue crystal optical metrology double-crystal topography anticlastic curvature ray-tracing measurement research papers Source Type: research