scholarly journals Development of Fluorescence XAFS System in Soft X-Ray Region Toward Operando Conditions Using Polycapillary X-Ray Lens

2016 ◽  
Vol 14 (0) ◽  
pp. 35-38 ◽  
Author(s):  
Mitsunori Honda ◽  
Iwao Shimoyama ◽  
Yuji Baba ◽  
Shinichi Suzuki ◽  
Yoshihiro Okamoto ◽  
...  
Keyword(s):  
X Ray ◽  
Fluorescence Xafs

A fluorescence XAFS measurement instrument in the soft x-ray region toward observation under operando conditions

2015 ◽  
Vol 86 (3) ◽  
pp. 035103 ◽  
Author(s):  
M. Honda ◽  
Y. Baba ◽  
I. Shimoyama ◽  
T. Sekiguchi
Keyword(s):  
Measurement Instrument ◽  
X Ray ◽  
Fluorescence Xafs

In situ back-side illumination fluorescence XAFS (BI-FXAFS) studies on platinum nanoparticles deposited on a HOPG surface as a model fuel cell: a new approach to the Pt-HOPG electrode/electrolyte interface

2014 ◽  
Vol 16 (27) ◽  
pp. 13748-13754 ◽  
Author(s):  
Hiromitsu Uehara ◽  
Yohei Uemura ◽  
Takafumi Ogawa ◽  
Kentaro Kono ◽  
Ryoichi Ueno ◽  
...  
Keyword(s):  
Fine Structure ◽  
Fuel Cell ◽  
Back Side ◽  
New Approach ◽  
X Ray ◽  
Model Fuel ◽  
Fluorescence Xafs ◽  
X Ray Absorption ◽  
Side Illumination

We measured the in situ polarization-dependent X-ray absorption fine structure of PtNPs deposited on a flat HOPG substrate.

New transmission-type X-ray filters consisting of amorphous multilayer films

1998 ◽  
Vol 5 (3) ◽  
pp. 603-605
Author(s):  
Yasuo Takagi ◽  
Muneyuki Imafuku
Keyword(s):  
Multilayer Films ◽  
X Rays ◽  
Solid State Detector ◽  
Sputtering Deposition ◽  
X Ray ◽  
Dependent Absorption ◽  
Diffraction Peaks ◽  
Sputter Deposited ◽  
Fluorescence Xafs ◽  
State Detector

New transmission-type X-ray filters have been developed. The filters consist of X-ray-amorphous metal (less than 30 Å)/metalloid (∼10 Å) multilayer films sputter-deposited on X-ray-transparent polymer substrates. Such metal/metalloid multilayer films show only very broad diffraction peaks, since the metal and metalloid layers forming the multilayer films are usually X-ray amorphous if the layers are sufficiently thin. The filters use the wavelength-dependent absorption phenomena near absorption edges of elements to reduce the intensity of transmitted X-rays, without generating any crystalline sharp peaks which cause serious problems in experiments such as fluorescence XAFS measurements. The multilayer-film filters were prepared by a multi-target magnetron sputtering deposition technique, paying special attention to the homogeneity of the layer thickness by spinning substrates of the films. The filters are useful in reducing the intensity of undesirable fluorescence emissions and improving the signal-to-background ratios of data acquired in various measurements using a solid-state detector.

Quick Fluorescence XAFS: A Technique for Recording Fluorescence X-ray Absorption Spectra during Chemical/Biochemical Reactions

1993 ◽  
Vol 32 (S2) ◽  
pp. 192 ◽  
Author(s):  
Barry R. Dobson ◽  
S. Samar Hasnain ◽  
Margarete Neu ◽  
Christine A. Ramsdale ◽  
Lorretta M. Murphy
Keyword(s):  
Absorption Spectra ◽  
Biochemical Reactions ◽  
X Ray ◽  
Fluorescence Xafs ◽  
X Ray Absorption

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Iron K-Line Emission from X-Ray Binaries

1988 ◽  
Vol 102 ◽  
pp. 47-50
Author(s):  
K. Masai ◽  
S. Hayakawa ◽  
F. Nagase
Keyword(s):  
Accretion Disk ◽  
Radiative Recombination ◽  
Characteristic Temperature ◽  
Line Emission ◽  
Ionization Front ◽  
Continuum Radiation ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx> 10 keV is likely due to fluorescence outside the He II ionization front.

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