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Journal of Synchrotron Radiation

Max O Wiedorn, Salah Awel, Andrew J Morgan, Miriam Barthelmess, Richard Bean, Kenneth R Beyerlein, Leonard M G Chavas, Niko Eckerskorn, Holger Fleckenstein, Michael Heymann, Daniel A Horke, Juraj Knoška, Valerio Mariani, Dominik Oberthür, Nils Roth, Oleksandr Yefanov, Anton Barty, Saša Bajt, Jochen Küpper, Andrei V Rode, Richard A Kirian, Henry N Chapman
The success of diffraction experiments from weakly scattering samples strongly depends on achieving an optimal signal-to-noise ratio. This is particularly important in single-particle imaging experiments where diffraction signals are typically very weak and the experiments are often accompanied by significant background scattering. A simple way to tremendously reduce background scattering by placing an aperture downstream of the sample has been developed and its application in a single-particle X-ray imaging experiment at FLASH is demonstrated...
November 1, 2017: Journal of Synchrotron Radiation
Tomáš Faragó, Petr Mikulík, Alexey Ershov, Matthias Vogelgesang, Daniel Hänschke, Tilo Baumbach
An open-source framework for conducting a broad range of virtual X-ray imaging experiments, syris, is presented. The simulated wavefield created by a source propagates through an arbitrary number of objects until it reaches a detector. The objects in the light path and the source are time-dependent, which enables simulations of dynamic experiments, e.g. four-dimensional time-resolved tomography and laminography. The high-level interface of syris is written in Python and its modularity makes the framework very flexible...
November 1, 2017: Journal of Synchrotron Radiation
Sangsul Lee, Ik Hwan Kwon, Jae Young Kim, Sung Sun Yang, Sechang Kang, Jun Lim
For spectral imaging of chemical distributions using X-ray absorption near-edge structure (XANES) spectra, a modified double-crystal monochromator, a focusing plane mirrors system and a newly developed fluorescence-type X-ray beam-position monitoring and feedback system have been implemented. This major hardware upgrade provides a sufficiently stable X-ray source during energy scanning of more than hundreds of eV for acquisition of reliable XANES spectra in two-dimensional and three-dimensional images. In recent pilot studies discussed in this paper, heavy-metal uptake by plant roots in vivo and iron's phase distribution in the lithium-iron-phosphate cathode of a lithium-ion battery have been imaged...
November 1, 2017: Journal of Synchrotron Radiation
Paromita Sarbadhikary, Alok Dube
The combination of synchrotron X-ray radiation and metal-based radiosensitizer is a novel form of photon activation therapy which offers the advantage of treating malignant tumors with greater efficacy and higher precision than conventional radiation therapy. In this study the anticancer cytotoxic efficacy of a new chlorophyll derivative, iodinated chlorin p6 copper complex (ICp6-Cu), combined with synchrotron X-ray radiation (8-10 keV) in two human oral cancer cell lines is explored. Pre-treatment of cells with 20 µM and 30 µM ICp6-Cu for 3 h was found to enhance the X-ray-induced cytotoxicity with sensitization enhancement ratios of 1...
November 1, 2017: Journal of Synchrotron Radiation
Rongbiao Tang, Fuhua Yan, Guo Yuan Yang, Ke Min Chen
Preoperative portal vein embolization (PVE) is employed clinically to avoid postoperative liver insufficiency. Animal models are usually used to study PVE in terms of mechanisms and pathophysiological changes. PVE is formerly monitored by conventional absorption contrast imaging (ACI) with iodine contrast agent. However, the side effects induced by iodine can give rise to animal damage and death. In this study, the feasibility of using phase contrast imaging (PCI) to show PVE using homemade CO2 microbubbles in living rats has been investigated...
November 1, 2017: Journal of Synchrotron Radiation
Rajmund Mokso, Christian M Schlepütz, Gerd Theidel, Heiner Billich, Elmar Schmid, Tine Celcer, Gordan Mikuljan, Leonardo Sala, Federica Marone, Nick Schlumpf, Marco Stampanoni
Owing to recent developments in CMOS technology, it is now possible to exploit tomographic microscopy at third-generation synchrotron facilities with unprecedented speeds. Despite this rapid technical progress, one crucial limitation for the investigation of realistic dynamic systems has remained: a generally short total acquisition time at high frame rates due to the limited internal memory of available detectors. To address and solve this shortcoming, a new detection and readout system, coined GigaFRoST, has been developed based on a commercial CMOS sensor, acquiring and streaming data continuously at 7...
November 1, 2017: Journal of Synchrotron Radiation
Marco Voltolini, Abdelmoula Haboub, Shan Dou, Tae Hyuk Kwon, Alastair A MacDowell, Dilworth Y Parkinson, Jonathan Ajo-Franklin
Continuous improvements at X-ray imaging beamlines at synchrotron light sources have made dynamic synchrotron X-ray micro-computed tomography (SXR-µCT) experiments more routinely available to users, with a rapid increase in demand given its tremendous potential in very diverse areas. In this work a survey of five different four-dimensional SXR-µCT experiments is presented, examining five different parameters linked to the evolution of the investigated system, and tackling problems in different areas in earth sciences...
November 1, 2017: Journal of Synchrotron Radiation
Alberto Mittone, Ilja Manakov, Ludovic Broche, Christophe Jarnias, Paola Coan, Alberto Bravin
The detection system is a key part of any imaging station. Here the performance of the novel sCMOS-based detection system installed at the ID17 biomedical beamline of the European Synchrotron Radiation Facility and dedicated to high-resolution computed-tomography imaging is analysed. The system consists of an X-ray-visible-light converter, a visible-light optics and a PCO.Edge5.5 sCMOS detector. Measurements of the optical characteristics, the linearity of the system, the detection lag, the modulation transfer function, the normalized power spectrum, the detective quantum efficiency and the photon transfer curve are presented and discussed...
November 1, 2017: Journal of Synchrotron Radiation
Shenghui Liao, Shuangfei Ni, Yong Cao, Xianzhen Yin, Tianding Wu, Hongbin Lu, Jianzhong Hu, Hao Wu, Ye Lang
Many published literature sources have described the histopathological characteristics of post-traumatic syringomyelia (PTS). However, three-dimensional (3D) visualization studies of PTS have been limited due to the lack of reliable 3D imaging techniques. In this study, the imaging efficiency of propagation-based synchrotron radiation microtomography (PB-SRµCT) was determined to detect the 3D morphology of the cavity and surrounding microvasculature network in a rat model of PTS. The rat model of PTS was established using the infinite horizon impactor to produce spinal cord injury (SCI), followed by a subarachnoid injection of kaolin to produce arachnoiditis...
November 1, 2017: Journal of Synchrotron Radiation
Amardeep Bharti, Ashish K Agrawal, Balwant Singh, Sanjeev Gautam, Navdeep Goyal
Plasmonic metal nanostructures have a significant impact on a diverse domain of fields, including photocatalysis, antibacterial, drug vector, biosensors, photovoltaic cell, optical and electronic devices. Metal nanoparticles (MNps) are the simplest nanostructure promising ultrahigh stability, ease of manufacturing and tunable optical response. Silver nanoparticles (AgNp) dominate in the class of MNps because of their relatively high abundance, chemical activity and unique physical properties. Although MNps offer the desired physical properties, most of the synthesis and fabrication methods lag at the electronic grade due to an unbidden secondary product as a result of the direct chemical reduction process...
November 1, 2017: Journal of Synchrotron Radiation
Álvaro Martín Ortega, Ana Lacoste, Stéphane Béchu, Alexandre Bès, Nader Sadeghi
X-ray gas attenuators are used in high-energy synchrotron beamlines as high-pass filters to reduce the incident power on downstream optical elements. The absorption of the X-ray beam ionizes and heats up the gas, creating plasma around the beam path and hence temperature and density gradients between the center and the walls of the attenuator vessel. The objective of this work is to demonstrate experimentally the generation of plasma by the X-ray beam and to investigate its spatial distribution by measuring some of its parameters, simultaneously with the X-ray power absorption...
November 1, 2017: Journal of Synchrotron Radiation
Mahsa Mokhtarzadeh, Karl F Ludwig
The recent development of surface growth studies using X-ray photon correlation spectroscopy in a grazing-incidence small-angle X-ray scattering (Co-GISAXS) geometry enables the investigation of dynamical processes during kinetic roughening in greater detail than was previously possible. In order to investigate the Co-GISAXS behavior expected from existing growth models, calculations and (2+1)-dimension simulations of linear Kuramoto-Sivashinsky and non-linear Kardar-Parisi-Zhang surface growth equations are presented which analyze the temporal correlation functions of the height-height structure factor...
November 1, 2017: Journal of Synchrotron Radiation
Georgi L Dakovski, Ming Fu Lin, Daniel S Damiani, William F Schlotter, Joshua J Turner, Dennis Nordlund, Hirohito Ogasawara
A method for measuring resonant inelastic X-ray scattering based on the conversion of X-ray photons into photoelectrons is presented. The setup is compact, relies on commercially available detectors, and offers significant flexibility. This method is demonstrated at the Linac Coherent Light Source with ∼0.5 eV resolution at the cobalt L3-edge, with signal rates comparable with traditional grating spectrometers.
November 1, 2017: Journal of Synchrotron Radiation
B Ravel, M Newville, J J Kas, J J Rehr
A theory program intended for use with extended X-ray-absorption fine structure (EXAFS) spectroscopy and based on the popular FEFF8 is presented. It provides an application programming interface designed to make it easy to integrate high-quality theory into EXAFS analysis software. This new code is then used to examine the impact of self-consistent scattering potentials on EXAFS data analysis by methodical testing of theoretical fitting standards against a curated suite of measured EXAFS data. For each data set, the results of a fit are compared using a well characterized structural model and theoretical fitting standards computed both with and without self-consistent potentials...
November 1, 2017: Journal of Synchrotron Radiation
Jan David Nicolas, Marten Bernhardt, Andrea Markus, Frauke Alves, Manfred Burghammer, Tim Salditt
A scanning X-ray diffraction study of cardiac tissue has been performed, covering the entire cross section of a mouse heart slice. To this end, moderate focusing by compound refractive lenses to micrometer spot size, continuous scanning, data acquisition by a fast single-photon-counting pixel detector, and fully automated analysis scripts have been combined. It was shown that a surprising amount of structural data can be harvested from such a scan, evaluating the local scattering intensity, interfilament spacing of the muscle tissue, the filament orientation, and the degree of anisotropy...
November 1, 2017: Journal of Synchrotron Radiation
Helen Mary Ginn, David Ian Stuart
Geometry correction is traditionally plagued by mis-fitting of correlated parameters, leading to local minima which prevent further improvements. Segmented detectors pose an enhanced risk of mis-fitting: even a minor confusion of detector distance and panel separation can prevent improvement in data quality. The slip-and-slide algorithm breaks down effects of the correlated parameters and their associated target functions in a fundamental shift in the approach to the problem. Parameters are never refined against the components of the data to which they are insensitive, providing a dramatic boost in the exploitation of information from a very small number of diffraction patterns...
November 1, 2017: Journal of Synchrotron Radiation
Mercedes Martinson, Nazanin Samadi, Xianbo Shi, Zunping Liu, Lahsen Assoufid, Dean Chapman
A bent Laue double-crystal monochromator system has been designed for vertically expanding the X-ray beam at the Canadian Light Source's BioMedical Imaging and Therapy beamlines. Expansion by a factor of 12 has been achieved without deteriorating the transverse coherence of the beam, allowing phase-based imaging techniques to be performed with high flux and a large field of view. However, preliminary studies revealed a lack of uniformity in the beam, presumed to be caused by imperfect bending of the silicon crystal wafers used in the system...
November 1, 2017: Journal of Synchrotron Radiation
S Gasilov, A Mittone, T Dos Santos Rolo, S Polyakov, S Zholudev, S Terentyev, V Blank, A Bravin, T Baumbach
In this work a double-crystal setup is employed to study compound refractive lenses made of single-crystal diamond. The point spread function of the lens is calculated taking into account the lens transmission, the wavefront aberrations, and the ultra-small-angle broadening of the X-ray beam. It is shown that, similarly to the wavefront aberrations, the ultra-small-angle scattering effects can significantly reduce the intensity gain and increase the focal spot size. The suggested approach can be particularly useful for the characterization of refractive X-ray lenses composed of many tens of unit lenses...
November 1, 2017: Journal of Synchrotron Radiation
John P Sutter, Lucia Alianelli
The shapes of single lens surfaces capable of focusing divergent and collimated beams without aberration have already been calculated. However, nanofocusing compound refractive lenses (CRLs) require many consecutive lens surfaces. Here a theoretical example of an X-ray nanofocusing CRL with 48 consecutive surfaces is studied. The surfaces on the downstream end of this CRL accept X-rays that are already converging toward a focus, and refract them toward a new focal point that is closer to the surface. This case, so far missing from the literature, is treated here...
November 1, 2017: Journal of Synchrotron Radiation
E Nazaretski, H Yan, K Lauer, N Bouet, X Huang, W Xu, J Zhou, D Shu, Y Hwu, Y S Chu
A hard X-ray scanning microscope installed at the Hard X-ray Nanoprobe beamline of the National Synchrotron Light Source II has been designed, constructed and commissioned. The microscope relies on a compact, high stiffness, low heat dissipation approach and utilizes two types of nanofocusing optics. It is capable of imaging with ∼15 nm × 15 nm spatial resolution using multilayer Laue lenses and 25 nm × 26 nm resolution using zone plates. Fluorescence, diffraction, absorption, differential phase contrast, ptychography and tomography are available as experimental techniques...
November 1, 2017: Journal of Synchrotron Radiation
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