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Journal of Synchrotron Radiation

Kaili Zhang, Gregory S Girolami, Josh Vura-Weis
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 ferrocenium cations and to propose alternative assignments for the electronic state of these cations responsible for the spectroscopic features...
September 1, 2018: Journal of Synchrotron Radiation
Nicolas Dauphas, Michael Y Hu, Erik M Baker, Justin Hu, Francois L H Tissot, E Ercan Alp, Mathieu Roskosz, Jiyong Zhao, Wenli Bi, Jin Liu, Jung Fu Lin, Nicole X Nie, Andrew Heard
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 Mössbauer isotopes such as 57 Fe, 83 Kr, 119 Sn, 151 Eu and 161 Dy...
September 1, 2018: Journal of Synchrotron Radiation
Siniša Veseli, Nicholas Schwarz, Collin Schmitz
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 is discussed, examples of its use have been provided and future development plans are outlined...
September 1, 2018: Journal of Synchrotron Radiation
Nicholas P Edwards, Samuel M Webb, Courtney M Krest, Douglas van Campen, Phillip L Manning, Roy A Wogelius, Uwe Bergmann
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 µm 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...
September 1, 2018: Journal of Synchrotron Radiation
Shusaku Hayama, Graham Duller, John P Sutter, Monica Amboage, Roberto Boada, Adam Freeman, Luke Keenan, Brian Nutter, Leo Cahill, Pete Leicester, Ben Kemp, Nico Rubies, Sofia Diaz-Moreno
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...
September 1, 2018: Journal of Synchrotron Radiation
Tomasz W Wysokinski, Michel Renier, Pekka Suortti, George Belev, Léo Rousset, Madison Adam, Denise Miller, Norman Huber, L Dean Chapman
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 µm. A pair of 2 mm-thick Si(111) bent Laue-type crystals were used in fixed-exit beam mode with a 16 mm vertical beam offset and the first crystal water-cooled...
September 1, 2018: Journal of Synchrotron Radiation
U K Goutam, R K Sharma, J Singh, K Dutta, U S Sule, R Pradeep, S C Gadkari
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...
September 1, 2018: Journal of Synchrotron Radiation
Benjamin Erk, Jan P Müller, Cédric Bomme, Rebecca Boll, Günter Brenner, Henry N Chapman, Jonathan Correa, Stefan Düsterer, Siarhei Dziarzhytski, Stefan Eisebitt, Heinz Graafsma, Sören Grunewald, Lars Gumprecht, Robert Hartmann, Günter Hauser, Barbara Keitel, Clemens von Korff Schmising, Marion Kuhlmann, Bastian Manschwetus, Laurent Mercadier, Erland Müller, Christopher Passow, Elke Plönjes, Daniel Ramm, Dimitrios Rompotis, Artem Rudenko, Daniela Rupp, Mario Sauppe, Frank Siewert, Dieter Schlosser, Lothar Strüder, Angad Swiderski, Simone Techert, Kai Tiedtke, Thomas Tilp, Rolf Treusch, Ilme Schlichting, Joachim Ullrich, Robert Moshammer, Thomas Möller, Daniel Rolles
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...
September 1, 2018: Journal of Synchrotron Radiation
Mario Sauppe, Dimitrios Rompotis, Benjamin Erk, Sadia Bari, Tobias Bischoff, Rebecca Boll, Cédric Bomme, Christoph Bostedt, Simon Dörner, Stefan Düsterer, Torsten Feigl, Leonie Flückiger, Tais Gorkhover, Katharina Kolatzki, Bruno Langbehn, Nils Monserud, Erland Müller, Jan P Müller, Christopher Passow, Daniel Ramm, Daniel Rolles, Kaja Schubert, Lucas Schwob, Björn Senfftleben, Rolf Treusch, Anatoli Ulmer, Holger Weigelt, Jannis Zimbalski, Julian Zimmermann, Thomas Möller, Daniela Rupp
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...
September 1, 2018: Journal of Synchrotron Radiation
Steve M Heald, Eric M Dufresne
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.
September 1, 2018: Journal of Synchrotron Radiation
M Laabs, N Neumann, B Green, N Awari, J Deinert, S Kovalev, D Plettemeier, M Gensch
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 up to 5 GHz repetition rates...
September 1, 2018: Journal of Synchrotron Radiation
Francisco García-Moreno, Paul H Kamm, Tillmann R Neu, John Banhart
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...
September 1, 2018: Journal of Synchrotron Radiation
Colin Nave
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 metals...
September 1, 2018: Journal of Synchrotron Radiation
Rafael Vescovi, Ming Du, Vincent de Andrade, William Scullin, Dogˇa Gürsoy, Chris Jacobsen
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...
September 1, 2018: Journal of Synchrotron Radiation
Niranjan D Parab, Cang Zhao, Ross Cunningham, Luis I Escano, Kamel Fezzaa, Wes Everhart, Anthony D Rollett, Lianyi Chen, Tao Sun
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...
September 1, 2018: Journal of Synchrotron Radiation
Serena Pacilè, Patrycja Baran, Christian Dullin, Matthew Dimmock, Darren Lockie, Jeannine Missbach-Guntner, Harry Quiney, Mikkaela McCormack, Sheridan Mayo, Darren Thompson, Yakov Nesterets, Chris Hall, Konstantin Pavlov, Zdenka Prodanovic, Maura Tonutti, Agostino Accardo, Jane Fox, Seyedamir Tavakoli Taba, Sarah Lewis, Patrick Brennan, Daniel Hausermann, Giuliana Tromba, Tim Gureyev
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...
September 1, 2018: Journal of Synchrotron Radiation
Yuqing Zhao, Mengyu Sun, Dongjiang Ji, Changhong Cong, Wenjuan Lv, Qi Zhao, Lili Qin, Jianbo Jian, Xiaodong Chen, Chunhong Hu
In-line X-ray phase-contrast computed tomography (IL-PCCT) can reveal fine inner structures for low-Z materials (e.g. biological soft tissues), and shows high potential to become clinically applicable. Typically, IL-PCCT utilizes filtered back-projection (FBP) as the standard reconstruction algorithm. However, the FBP algorithm requires a large amount of projection data, and subsequently a large radiation dose is needed to reconstruct a high-quality image, which hampers its clinical application in IL-PCCT. 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...
September 1, 2018: Journal of Synchrotron Radiation
Yoshinori Kotani, Yasunori Senba, Kentaro Toyoki, David Billington, Hiroyuki Okazaki, Akira Yasui, Wakana Ueno, Haruhiko Ohashi, Satoshi Hirosawa, Yu Shiratsuchi, Tetsuya Nakamura
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...
September 1, 2018: Journal of Synchrotron Radiation
C Jansing, H Wahab, H Timmers, A Gaupp, H C Mertins
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 escape length...
September 1, 2018: Journal of Synchrotron Radiation
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