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synchrotron radiation

Takashi Imazono
A Mo/Si multilayer-coated photodiode detector (MP) for beam intensity monitoring was prototyped and characterized using synchrotron radiation and X-ray laser (XRL) sources in order to perform polarization analysis of a laser-driven plasma soft XRL generated from nickel-like silver plasma. At a wavelength of 13.9 nm and an angle of incidence of 45°, the s-polarization reflectance is 0.525 and shows a strong positive correlation with the transmittance, corresponding to the photodiode current generated by the MP...
July 20, 2017: Applied Optics
S Maidul Haque, Rajnarayan De, S Tripathi, C Mukherjee, A K Yadav, Dibyendu Bhattacharyya, S N Jha, N K Sahoo
Gadolinium oxide is an excellent optical material that offers high transmission in a wide wavelength range of 200-1600 nm and exhibits a high bulk refractive index of ∼1.80 at 550 nm. In the present study, a set of Gd2O3 thin films has been deposited on fused silica substrates by RF sputtering of a Gd2O3 target under various O2 to Ar flow ratios. The samples have been characterized by grazing incidence x-ray diffraction (GIXRD) to study the long range structural behavior, by GIXR to study density and surface roughness of the films, by atomic force microscopy measurements to study morphological properties, by Rutherford backscattering measurements for compositional studies, and by transmission spectrophotometry and spectroscopic ellipsometry techniques to study their optical properties...
August 1, 2017: Applied Optics
Piyali Sarkar, Arup Biswas, Rajnarayan De, K Divakar Rao, Subir Ghosh, M H Modi, Siju John, H C Barshilia, Dibyendu Bhattacharyya, Naba Kishor Sahoo
The DC magnetron sputter grown Co/Ti multilayers, with ultra-low bi-layer thicknesses and with Co layers deposited under mixed ambience of argon and dry air, have been investigated for use in the water window soft x-ray regime of 23-44 Å. Initially, deposition parameters have been optimized for obtaining smooth and continuous low thickness Co and Ti single-layer films, and, then, multilayers with five bi-layers of various bi-layer thicknesses were deposited. The samples have been primarily characterized by the grazing incidence x-ray reflectivity (GIXR) measurements with a hard x-ray laboratory source...
September 20, 2017: Applied Optics
Hiroyuki Yamane, Nobuhiro Kosugi
The electronic structure of 7,7,8,8-tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-TCNQ (F4TCNQ) monolayers on Au(111) has been investigated by means of angle-resolved photoemission spectroscopy (ARPES) with synchrotron radiation. In contrast to the physisorbed TCNQ/Au(111) interface, the high-resolution core-level photoemission spectra and the low-energy electron diffraction at the F4TCNQ/Au(111) interface show evidences for the strong charge transfer (CT) from Au to F4TCNQ and for the Au-atom segregation from the underlying Au(111) surface, suggesting a possible origin of the spontaneous formation of the two-dimensional F4TCNQ-Au network...
October 18, 2017: Journal of Physical Chemistry Letters
Martin D de Jonge, Andrew M Kingston, Nader Afshar, Jan Garrevoet, Robin Kirkham, Gary Ruben, Glenn R Myers, Shane J Latham, Daryl L Howard, David J Paterson, Christopher G Ryan, Gawain McColl
Scanning X-ray fluorescence tomography was once considered impractical due to prohibitive measurement time requirements but is now common for investigating metal distributions within small systems. A recent look-ahead to the possibilities of 4(th)-generation synchrotron light sources [J. Synchrotron. Radiat. 21, 1031 (2014)] raised the possibility of a spiral-scanning measurement scheme where motion overheads are almost completely eliminated. Here we demonstrate the spiral scanning measurement and use Fourier ring correlation analysis to interrogate sources of resolution degradation...
September 18, 2017: Optics Express
Maxime Lebugle, Marianne Liebi, Klaus Wakonig, Vitaliy A Guzenko, Mirko Holler, Andreas Menzel, Manuel Guizar-Sicairos, Ana Diaz, Christian David
High-efficiency microfocusing of multi-keV X-rays at synchrotron sources is highly profitable for spatially resolved structural analysis of many kinds. Because radiation from synchrotron sources is typically elongated along the horizontal dimension, generating a microbeam that is isotropic in size requires a carefully designed optics system. Here we report on using a combination of a horizontally tunable slit downstream of the undulator source with elliptical diffractive Fresnel zone plates. We demonstrate the arrangement in context of small-angle X-ray scattering experiments, obtaining a microbeam of 2...
September 4, 2017: Optics Express
Johannes Hagemann, Tim Salditt
We present a phase reconstruction scheme for X-ray near-field holographic imaging based on a separability constraint for probe and object. In order to achieve this, we have devised an algorithm which requires only two measurements - with and without an object in the beam. This scheme is advantageous if the standard flat-field correction fails and a full ptychographic dataset can not be acquired, since either object or probe are dynamic. The scheme is validated by numerical simulations and by a proof-of-concept experiment using highly focused undulator radiation of the beamline ID16a of the European Synchrotron Radiation Facility (ESRF)...
September 4, 2017: Optics Express
Ruben A Dilanian, Victor Streltsov, Hannah D Coughlan, Harry M Quiney, Andrew V Martin, Nectarios Klonis, Con Dogovski, Sébastien Boutet, Marc Messerschmidt, Garth J Williams, Sophie Williams, Nicholas W Phillips, Keith A Nugent, Leann Tilley, Brian Abbey
The recent availability of extremely intense, femtosecond X-ray free-electron laser (XFEL) sources has spurred the development of serial femtosecond nanocrystallography (SFX). Here, SFX is used to analyze nanoscale crystals of β-hematin, the synthetic form of hemozoin which is a waste by-product of the malaria parasite. This analysis reveals significant differences in β-hematin data collected during SFX and synchrotron crystallography experiments. To interpret these differences two possibilities are considered: structural differences between the nanocrystal and larger crystalline forms of β-hematin, and radiation damage...
October 1, 2017: Journal of Applied Crystallography
B Zeller-Plumhoff, K R Daly, G F Clough, P Schneider, T Roose
The supply of oxygen in sufficient quantity is vital for the correct functioning of all organs in the human body, especially for skeletal muscle during exercise. Traditionally, microvascular oxygen supply capability is assessed by the analysis of morphological measures on transverse cross-sections of muscle, e.g. capillary density or capillary-to-fibre ratio. In this work, we investigate the relationship between microvascular structure and muscle tissue oxygenation in mice. Phase contrast imaging was performed using synchrotron radiation computed tomography (SR CT) to visualize red blood cells (RBCs) within the microvasculature in mouse soleus muscle...
October 2017: Journal of the Royal Society, Interface
Soha Bazyar, Christina R Inscoe, E Timothy O'Brien Iii, Otto Z Zhou, Yueh Z Lee
Minibeam radiation therapy (MBRT) delivers ultrahigh dose of X-ray (≥100 Gy) in 200-1000 μm beams (peaks), separated by wider non-irradiated regions (valleys) usually as a single temporal fraction. Preclinical studies performed at synchrotron facilities revealed that MBRT is able to ablate tumors while maintaining normal tissue integrity. The main purpose of present study was to develop an efficient and accessible method to perform MBRT using a conventional X-ray irradiator. We then tested this new method both in-vitro and in-vivo...
October 10, 2017: Physics in Medicine and Biology
Simone Cagno, Dag Anders Brede, Gert Nuyts, Frederik Vanmeert, Alexandra Pacureanu, Remi Tucoulou, Peter Cloetens, Gerald Falkenberg, Koen Janssens, Brit Salbu, Ole Christian Lind
Synchrotron radiation phase contrast nano-CT and (2D and 3D) nano-XRF were used to investigate the internal distribution of engineered Co nanoparticles in exposed individuals of the nematode Caenorhabiditis elegans. Whole nematodes and selected tissues and organs were 3D rendered: anatomical 3D renderings with 50 nm voxel size enabled the visualization of 50-200 nm sized, spherical nanoparticle aggregates within intact C. elegans. A 20 x 37 nm2 high-brilliance beam was employed to obtain XRF elemental distribution maps of entire nematodes or anatomical details such as embryos, which could be compared with the CT data...
October 10, 2017: Analytical Chemistry
Marina Gromova, Aurelie Lefrancois, Louis Vaure, Fabio Agnese, Dmitry Aldakov, Axel Maurice, David Djurado, Colette Lebrun, Arnaud de Geyer, Tobias U Schulli, Stéphanie Pouget, Peter Reiss
Ternary metal chalcogenide nanocrystals (NCs) offer exciting opportunities as novel materials to be explored on the nanoscale showing optoelectronic properties tunable with size and composition. CuInS2 (CIS) NCs are the most widely studied representatives of this family as they can be easily prepared with good size control and in high yield by reacting the metal precursors (copper iodide and indium acetate) in dodecanethiol (DDT). Despite the widespread use of this synthesis method both the reaction mechanism and the surface state of the obtained NCs remain elusive...
October 10, 2017: Journal of the American Chemical Society
Chenyang Shi, Rattavut Teerakapibal, Lian Yu, Geoff G Z Zhang
Using high-brilliance high-energy synchrotron X-ray radiation, for the first time the total scattering of a thin organic glass film deposited on a strongly scattering inorganic substrate has been measured in transmission mode. The organic thin film was composed of the weakly scattering pharmaceutical substance indomethacin in the amorphous state. The film was 130 µm thick atop a borosilicate glass substrate of equal thickness. The atomic pair distribution function derived from the thin-film measurement is in excellent agreement with that from bulk measurements...
September 1, 2017: IUCrJ
Masaki Yamamoto, Kunio Hirata, Keitaro Yamashita, Kazuya Hasegawa, Go Ueno, Hideo Ago, Takashi Kumasaka
The progress in X-ray microbeam applications using synchrotron radiation is beneficial to structure determination from macromolecular microcrystals such as small in meso crystals. However, the high intensity of microbeams causes severe radiation damage, which worsens both the statistical quality of diffraction data and their resolution, and in the worst cases results in the failure of structure determination. Even in the event of successful structure determination, site-specific damage can lead to the misinterpretation of structural features...
September 1, 2017: IUCrJ
Carolyne Albert, John Jameson, Sergey Tarima, Peter Smith, Gerald Harris
Children with severe osteogenesis imperfecta (OI) typically experience numerous fractures and progressive skeletal deformities over their lifetime. Recent studies proposed finite element models to assess fracture risk and guide clinicians in determining appropriate intervention in children with OI, but lack of appropriate material property inputs remains a challenge. This study aimed to characterize macroscopic anisotropic cortical bone material properties and investigate relationships with bone density measures in children with severe OI...
September 14, 2017: Journal of Biomechanics
Maarten F Heringa, Jay Gates Slowik, Maximilian Goldmann, Ruth Signorell, Patrick Hemberger, Andras Bodi
The valence threshold photoionization of oleic acid has been studied using synchrotron VUV radiation and imaging photoelectron photoion coincidence (iPEPICO) spectroscopy. An oleic acid aerosol beam was impacted on a copper thermodesorber, heated to 130 °C, to evaporate the particles quantitatively. Upon threshold photoionization, oleic acid produces the intact parent ion first, followed by dehydration at higher energies. Starting at ca. 10 eV, a large number of fragment ions slowly rise suggesting several fragmentation coordinates with quasi-degenerate activation energies...
October 7, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Sarah Nasser, Alain Hédoux, Alexandre Giuliani, Cécile Le Floch-Fouéré, Véronique Santé-Lhoutellier, Isabelle de Waele, Guillaume Delaplace
BACKGROUND: Synchrotron Radiation Circular Dichroism (SRCD) and Fourier Transform Infrared (FTIR) spectroscopy were used to examine the conformation evolution of micellar casein (MC) powder during storage and to determine whether the spectral changes could be related to their solubility evolution. RESULTS: A loss in intensity of SRCD spectra as a function of storage time has been observed. Quantification of secondary structures revealed losses of α-helix content during storage...
October 5, 2017: Journal of the Science of Food and Agriculture
Stefan Bartzsch, Uwe Oelfke
Currently hard coherent x-ray radiation at high photon fluxes can only be produced with large and expensive radiation sources, such as 3rd generation synchrotrons. Especially in medicine, this limitation prevents various promising developments in imaging and therapy, such as microbeam radiation therapy from being translated into clinical practice. Here we present a new concept of highly brilliant x-ray sources, line focus x-ray tubes (LFXTs), which may serve as a powerful and cheap alternative to synchrotrons and a range of other existing technologies...
October 4, 2017: Physics in Medicine and Biology
Michael L Baker, Michael W Mara, James J Yan, Keith O Hodgson, Britt Hedman, Edward I Solomon
Continual advancements in the development of synchrotron radiation sources have resulted in X-ray based spectroscopic techniques capable of probing the electronic and structural properties of numerous systems. This review gives an overview of the application of metal K-edge and L-edge X-ray absorption spectroscopy (XAS), as well as K resonant inelastic X-ray scattering (RIXS), to the study of electronic structure in transition metal sites with emphasis on experimentally quantifying 3d orbital covalency. The specific sensitivities of K-edge XAS, L-edge XAS, and RIXS are discussed emphasizing the complementary nature of the methods...
August 15, 2017: Coordination Chemistry Reviews
Makina Saito, Ryo Masuda, Yoshitaka Yoda, Makoto Seto
We developed a multi-line time-domain interferometry (TDI) system using 14.4 keV Mössbauer gamma rays with natural energy widths of 4.66 neV from (57)Fe nuclei excited using synchrotron radiation. Electron density fluctuations can be detected at unique lengths ranging from 0.1 nm to a few nm on time scales from several nanoseconds to the sub-microsecond order by quasi-elastic gamma-ray scattering (QGS) experiments using multi-line TDI. In this report, we generalize the established expression for a time spectrum measured using an identical single-line gamma-ray emitter pair to the case of a nonidentical pair of multi-line gamma-ray emitters by considering the finite energy width of the incident synchrotron radiation...
October 2, 2017: Scientific Reports
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