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Journal of Synchrotron Radiation

Shibo Xi, Lucas Santiago Borgna, Lirong Zheng, Yonghua Du, Tiandou Hu
In this report, AI-BL1.0, an open-source Labview-based program for automatic on-line beamline optimization, is presented. The optimization algorithms used in the program are Genetic Algorithm and Differential Evolution. Efficiency was improved by use of a strategy known as Observer Mode for Evolutionary Algorithm. The program was constructed and validated at the XAFCA beamline of the Singapore Synchrotron Light Source and 1W1B beamline of the Beijing Synchrotron Radiation Facility.
January 1, 2017: Journal of Synchrotron Radiation
Matthias Muntwiler, Jun Zhang, Roland Stania, Fumihiko Matsui, Peter Oberta, Uwe Flechsig, Luc Patthey, Christoph Quitmann, Thilo Glatzel, Roland Widmer, Ernst Meyer, Thomas A Jung, Philipp Aebi, Roman Fasel, Thomas Greber
The Photo-Emission and Atomic Resolution Laboratory (PEARL) is a new soft X-ray beamline and surface science laboratory at the Swiss Light Source. PEARL is dedicated to the structural characterization of local bonding geometry at surfaces and interfaces of novel materials, in particular of molecular adsorbates, nanostructured surfaces, and surfaces of complex materials. The main experimental techniques are soft X-ray photoelectron spectroscopy, photoelectron diffraction, and scanning tunneling microscopy (STM)...
January 1, 2017: Journal of Synchrotron Radiation
Samuli Urpelainen, Conny Såthe, Walan Grizolli, Marcus Agåker, Ashley R Head, Margit Andersson, Shih Wen Huang, Brian N Jensen, Erik Wallén, Hamed Tarawneh, Rami Sankari, Ralf Nyholm, Mirjam Lindberg, Peter Sjöblom, Niclas Johansson, Benjamin N Reinecke, M Alif Arman, Lindsay R Merte, Jan Knudsen, Joachim Schnadt, Jesper N Andersen, Franz Hennies
SPECIES is an undulator-based soft X-ray beamline that replaced the old I511 beamline at the MAX II storage ring. SPECIES is aimed at high-resolution ambient-pressure X-ray photoelectron spectroscopy (APXPS), near-edge X-ray absorption fine-structure (NEXAFS), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS) experiments. The beamline has two branches that use a common elliptically polarizing undulator and monochromator. The beam is switched between the two branches by changing the focusing optics after the monochromator...
January 1, 2017: Journal of Synchrotron Radiation
Nobuhisa Watanabe, Takayuki Nagae, Yusuke Yamada, Ayana Tomita, Naohiro Matsugaki, Masao Tabuchi
The protein crystallography beamline BL2S1, constructed at one of the 5 T superconducting bending-magnet ports of the Aichi synchrotron, is available to users associated with academic and industrial organizations. The beamline is mainly intended for use in X-ray diffraction measurements of single-crystals of macromolecules such as proteins and nucleic acids. Diffraction measurements for crystals of other materials are also possible, such as inorganic and organic compounds. BL2S1 covers the energy range 7-17 keV (1...
January 1, 2017: Journal of Synchrotron Radiation
Qunfeng Xiao, Aimee Maclennan, Yongfeng Hu, Mark Hackett, Peter Leinweber, Tsun Kong Sham
Micro-XAFS and chemical imaging techniques have been widely applied for studies of heterogeneously distributed systems, mostly in hard X-ray (>5 keV) or in soft X-ray (<1.5 keV) energies. The microprobe endstation of the SXRMB (soft X-ray microcharacterization beamline) at the Canadian Light Source is optimized at the medium energy (1.7-5 keV), and it has been recently commissioned and is available for general users. The technical design and the performance (energy range, beam size and flux) of the SXRMB microprobe are presented...
January 1, 2017: Journal of Synchrotron Radiation
Michele Cianci, Gleb Bourenkov, Guillaume Pompidor, Ivars Karpics, Johanna Kallio, Isabel Bento, Manfred Roessle, Florent Cipriani, Stefan Fiedler, Thomas R Schneider
The macromolecular crystallography P13 beamline is part of the European Molecular Biology Laboratory Integrated Facility for Structural Biology at PETRA III (DESY, Hamburg, Germany) and has been in user operation since mid-2013. P13 is tunable across the energy range from 4 to 17.5 keV to support crystallographic data acquisition exploiting a wide range of elemental absorption edges for experimental phase determination. An adaptive Kirkpatrick-Baez focusing system provides an X-ray beam with a high photon flux and tunable focus size to adapt to diverse experimental situations...
January 1, 2017: Journal of Synchrotron Radiation
M Jacquet, C Bruni
The goal of this paper is to express simply the number of photons impinging on a target in the framework of accelerator-based Compton X-ray sources. From the basic kinematics of Compton sources, analytic formulas for the angular and the spectral fluxes are established as functions of the energy spread or/and the angular divergence of the electron and the laser beams. Their detailed predictions are compared with Monte Carlo simulations. These analytic expressions allow one to compute in a simple and precise way the X-ray flux in a given angular acceptance and a given energy bandwidth, knowing the characteristics of the incoming beams...
January 1, 2017: Journal of Synchrotron Radiation
M Rauwolf, A Turyanskaya, A Roschger, J Prost, R Simon, O Scharf, M Radtke, T Schoonjans, A Guilherme Buzanich, K Klaushofer, P Wobrauschek, J G Hofstaetter, P Roschger, C Streli
In the quest for finding the ideal synchrotron-radiation-induced imaging method for the investigation of trace element distributions in human bone samples, experiments were performed using both a scanning confocal synchrotron radiation micro X-ray fluorescence (SR-µXRF) (FLUO beamline at ANKA) setup and a full-field color X-ray camera (BAMline at BESSY-II) setup. As zinc is a trace element of special interest in bone, the setups were optimized for its detection. The setups were compared with respect to count rate, required measurement time and spatial resolution...
January 1, 2017: Journal of Synchrotron Radiation
Zhong Yin, Hans Bernhard Peters, Ulrich Hahn, Josef Gonschior, Daniel Mierwaldt, Ivan Rajkovic, Jens Viefhaus, Christian Jooss, Simone Techert
A novel experimental setup is presented for resonant inelastic X-ray scattering investigations of solid and liquid samples in the soft X-ray region for studying the complex electronic configuration of (bio)chemical systems. The uniqueness of the apparatus is its high flexibility combined with optimal energy resolution and energy range ratio. The apparatus enables investigation of chemical analyses, which reflects the chemical imprints. The endstation is composed of a main sample chamber, a sample holder for either solid or liquid jet delivery system, and a soft X-ray grating spectrometer for 210-1250 eV with a resolving power of ∼1000...
January 1, 2017: Journal of Synchrotron Radiation
Alexander Bagger, Ties Haarman, Anna Puig Molina, Poul George Moses, Hirofumi Ishii, Nozomu Hiraoka, Yu Han Wu, Ku Ding Tsuei, Ib Chorkendorff, Frank De Groot
In this study an analysis strategy towards using the resonant inelastic X-ray scattering (RIXS) technique more effectively compared with X-ray absorption spectroscopy (XAS) is presented. In particular, the question of when RIXS brings extra information compared with XAS is addressed. To answer this question the RIXS plane is analysed using two models: (i) an exciton model and (ii) a continuum model. The continuum model describes the dipole pre-edge excitations while the exciton model describes the quadrupole excitations...
January 1, 2017: Journal of Synchrotron Radiation
Bradley M West, Michael Stuckelberger, April Jeffries, Srikanth Gangam, Barry Lai, Benjamin Stripe, Jörg Maser, Volker Rose, Stefan Vogt, Mariana I Bertoni
The study of a multilayered and multicomponent system by spatially resolved X-ray fluorescence microscopy poses unique challenges in achieving accurate quantification of elemental distributions. This is particularly true for the quantification of materials with high X-ray attenuation coefficients, depth-dependent composition variations and thickness variations. A widely applicable procedure for use after spectrum fitting and quantification is described. This procedure corrects the elemental distribution from the measured fluorescence signal, taking into account attenuation of the incident beam and generated fluorescence from multiple layers, and accounts for sample thickness variations...
January 1, 2017: Journal of Synchrotron Radiation
Andy Singh, Katharina Luening, Sean Brennan, Takayuki Homma, Nobuhiro Kubo, Stanisław H Nowak, Piero Pianetta
Total reflection X-ray fluorescence (TXRF) analysis is extensively used by the semiconductor industry for measuring trace metal contamination on silicon surfaces. In addition to determining the quantity of impurities on a surface, TXRF can reveal information about the vertical distribution of contaminants by measuring the fluorescence signal as a function of the angle of incidence. In this study, two samples were intentionally contaminated with copper in non-deoxygenated and deoxygenated ultrapure water (UPW) resulting in impurity profiles that were either atomically dispersed in a thin film or particle-like, respectively...
January 1, 2017: Journal of Synchrotron Radiation
Sylvain Petitgirard, Georg Spiekermann, Christopher Weis, Christoph Sahle, Christian Sternemann, Max Wilke
X-ray Raman scattering (XRS) spectroscopy is an inelastic scattering method that uses hard X-rays of the order of 10 keV to measure energy-loss spectra at absorption edges of light elements (Si, Mg, O etc.), with an energy resolution below 1 eV. The high-energy X-rays employed with this technique can penetrate thick or dense sample containers such as the diamond anvils employed in high-pressure cells. Here, we describe the use of custom-made conical miniature diamond anvils of less than 500 µm thickness which allow pressure generation of up to 70 GPa...
January 1, 2017: Journal of Synchrotron Radiation
Ch J Sahle, A D Rosa, M Rossi, V Cerantola, G Spiekermann, S Petitgirard, J Jacobs, S Huotari, M Moretti Sala, A Mirone
A method to separate the non-resonant inelastic X-ray scattering signal of a micro-metric sample contained inside a diamond anvil cell (DAC) from the signal originating from the high-pressure sample environment is described. Especially for high-pressure experiments, the parasitic signal originating from the diamond anvils, the gasket and/or the pressure medium can easily obscure the sample signal or even render the experiment impossible. Another severe complication for high-pressure non-resonant inelastic X-ray measurements, such as X-ray Raman scattering spectroscopy, can be the proximity of the desired sample edge energy to an absorption edge energy of elements constituting the DAC...
January 1, 2017: Journal of Synchrotron Radiation
Pierre Paleo, Michel Desvignes, Alessandro Mirone
A new method to reconstruct data acquired in a local tomography setup is proposed. This method uses an initial reconstruction and refines it by correcting the low-frequency artifacts, known as the cupping effect. A basis of Gaussian functions is used to correct the initial reconstruction. The coefficients of this basis are found by optimizing iteratively a fidelity term under the constraint of a known sub-region. Using a coarse basis reduces the degrees of freedom of the problem while actually correcting the cupping effect...
January 1, 2017: Journal of Synchrotron Radiation
Aaron D Parsons, Stephen W T Price, Nicola Wadeson, Mark Basham, Andrew M Beale, Alun W Ashton, J Frederick W Mosselmans, Paul D Quinn
With the development of fourth-generation high-brightness synchrotrons on the horizon, the already large volume of data that will be collected on imaging and mapping beamlines is set to increase by orders of magnitude. As such, an easy and accessible way of dealing with such large datasets as quickly as possible is required in order to be able to address the core scientific problems during the experimental data collection. Savu is an accessible and flexible big data processing framework that is able to deal with both the variety and the volume of data of multimodal and multidimensional scientific datasets output such as those from chemical tomography experiments on the I18 microfocus scanning beamline at Diamond Light Source...
January 1, 2017: Journal of Synchrotron Radiation
M Álvarez-Murga, J P Perrillat, Y Le Godec, F Bergame, J Philippe, A King, N Guignot, M Mezouar, J L Hodeau
X-ray tomography is a non-destructive three-dimensional imaging/microanalysis technique selective to a wide range of properties such as density, chemical composition, chemical states and crystallographic structure with extremely high sensitivity and spatial resolution. Here the development of in situ high-pressure high-temperature micro-tomography using a rotating module for the Paris-Edinburgh cell combined with synchrotron radiation is described. By rotating the sample chamber by 360°, the limited angular aperture of ordinary high-pressure cells is surmounted...
January 1, 2017: Journal of Synchrotron Radiation
A Fatima, S Kataria, L Baghel, K N Guruprasad, A K Agrawal, B Singh, P S Sarkar, T Shripathi, Y Kashyap
Experiments were conducted to study the effects of static magnetic fields (SMFs) on the venation network of soybean leaves using the synchrotron-based X-ray micro-imaging technique. The seeds of soybean (Glycine max, variety JS-335) were pretreated with different SMFs from 50 to 300 mT in steps of 50 mT for 1 h. The phase-contrast images obtained showed that, as the strength of the SMF increased, the area, width of the midrib, area of the midrib and minor vein of the middle leaflets of third trifoliate leaves also increased up to the SMF strength of 200 mT (1 h) and decreased thereafter...
January 1, 2017: Journal of Synchrotron Radiation
Clément Jailin, Jean Yves Buffière, François Hild, Martin Poncelet, Stéphane Roux
Seeking for quantitative tomographic images, it is of utmost importance to limit reconstruction artifacts. Detector imperfections, inhomogeneity of the incident beam, as classically observed in synchrotron beamlines, and their variations in time are a major cause of reconstruction bias such as `ring artifacts'. The present study aims at proposing a faithful estimate of the incident beam local intensity for each acquired projection during a scan, without revisiting the process of data acquisition itself. Actual flat-fields (acquired without specimen in the beam) and sinogram borders (when the specimen is present), which are not masked during the scan, are exploited to construct a suited instantaneous detector-wide flat-field...
January 1, 2017: Journal of Synchrotron Radiation
F Arcadu, F Marone, M Stampanoni
This paper introduces two novel strategies for iterative reconstruction of full interior tomography (FINT) data, i.e. when the field of view is entirely inside the object support and knowledge of the object support itself or the attenuation coefficients inside specific regions of interest are not available. The first approach is based on data edge-padding. The second technique creates an intermediate virtual sinogram, which is, then, reconstructed by a standard iterative algorithm. Both strategies are validated in the framework of the alternate direction method of multipliers plug-and-play with gridding projectors that provide a speed-up of three orders of magnitude with respect to standard operators implemented in real space...
January 1, 2017: Journal of Synchrotron Radiation
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