Photon interference effect in x-ray absorption spectra over a wide energy range

The first experimental applications of the undulator gap-scan technique in X-ray absorption spectroscopy are reported. The key advantage of this method is that during EXAFS scans the undulator is permanently tuned to the maximum of its emission peak in order to maximize the photon statistics. In X-MCD or spin-polarized EXAFS studies with a helical undulator of the Helios type, the polarization rate can also be kept almost constant over a wide energy range.

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Design of an ultrahigh-energy-resolution and wide-energy-range soft X-ray beamline

Journal of Synchrotron Radiation ◽

10.1107/s1600577513029093 ◽

2013 ◽

Vol 21 (1) ◽

pp. 273-279 ◽

Cited By ~ 9

Author(s):

L. Xue ◽

R. Reininger ◽

Y.-Q. Wu ◽

Y. Zou ◽

Z.-M. Xu ◽

...

Keyword(s):

Energy Range ◽

Energy Resolution ◽

Wide Energy Range ◽

Ultrahigh Energy ◽

Exit Slit ◽

Shanghai Synchrotron Radiation Facility ◽

X Ray ◽

Variable Line ◽

Line Spacing ◽

Wide Energy

A new ultrahigh-energy-resolution and wide-energy-range soft X-ray beamline has been designed and is under construction at the Shanghai Synchrotron Radiation Facility. The beamline has two branches: one dedicated to angle-resolved photoemission spectroscopy (ARPES) and the other to photoelectron emission microscopy (PEEM). The two branches share the same plane-grating monochromator, which is equipped with four variable-line-spacing gratings and covers the 20–2000 eV energy range. Two elliptically polarized undulators are employed to provide photons with variable polarization, linear in every inclination and circular. The expected energy resolution is approximately 10 meV at 1000 eV with a flux of more than 3 × 1010 photons s−1at the ARPES sample positions. The refocusing of both branches is based on Kirkpatrick–Baez pairs. The expected spot sizes when using a 10 µm exit slit are 15 µm × 5 µm (horizontal × vertical FWHM) at the ARPES station and 10 µm × 5 µm (horizontal × vertical FWHM) at the PEEM station. The use of plane optical elements upstream of the exit slit, a variable-line-spacing grating and a pre-mirror in the monochromator that allows the influence of the thermal deformation to be eliminated are essential for achieving the ultrahigh-energy resolution.

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Nanoscale determination of interatomic distance by ptychography-EXAFS method using advanced Kirkpatrick–Baez mirror focusing optics

Journal of Synchrotron Radiation ◽

10.1107/s1600577519017004 ◽

2020 ◽

Vol 27 (2) ◽

pp. 455-461

Author(s):

Makoto Hirose ◽

Kei Shimomura ◽

Takaya Higashino ◽

Nozomu Ishiguro ◽

Yukio Takahashi

Keyword(s):

Wide Energy Range ◽

X Rays ◽

Bulk Materials ◽

Interatomic Distances ◽

X Ray ◽

Combination Technique ◽

Wide Energy ◽

Diffraction Patterns ◽

X Ray Absorption

This work demonstrates a combination technique of X-ray ptychography and the extended X-ray absorption fine structure (ptychography-EXAFS) method, which can determine the interatomic distances of bulk materials at the nanoscale. In the high-resolution ptychography-EXAFS method, it is necessary to use high-intense coherent X-rays with a uniform wavefront in a wide energy range, hence a ptychographic measurement system installed with advanced Kirkpatrick–Baez mirror focusing optics is developed and its performance is evaluated. Ptychographic diffraction patterns of micrometre-size MnO particles are collected by using this system at 139 energies between 6.504 keV and 7.114 keV including the Mn K absorption edge, and then the EXAFS of MnO is derived from the reconstructed images. By analyzing the EXAFS spectra obtained from a 48 nm × 48 nm region, the nanoscale bond lengths of the first and second coordination shells of MnO are determined. The present approach has great potential to elucidate the unclarified relationship among the morphology, electronic state and atomic arrangement of inhomogeneous bulk materials with high spatial resolution.

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Large-Area X-ray Lithography System for LIGA Process Operating in Wide Energy Range of Synchrotron Radiation

Japanese Journal of Applied Physics ◽

10.1143/jjap.44.5500 ◽

2005 ◽

Vol 44 (7B) ◽

pp. 5500-5504 ◽

Cited By ~ 31

Author(s):

Yuichi Utsumi ◽

Takefumi Kishimoto ◽

Tadashi Hattori ◽

Hirotsugu Hara

Keyword(s):

Synchrotron Radiation ◽

Energy Range ◽

Wide Energy Range ◽

Large Area ◽

X Ray ◽

Wide Energy ◽

Area X ◽

Lithography System

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X-ray Variability of Blazars

Publications of the Astronomical Society of Australia ◽

10.1071/as01088 ◽

2002 ◽

Vol 19 (1) ◽

pp. 49-54 ◽

Cited By ~ 13

Author(s):

Elena Pian

Keyword(s):

Energy Range ◽

High Energy ◽

Space Missions ◽

Present Review ◽

Wide Energy Range ◽

Spectral Variability ◽

X Ray ◽

Energy Emission ◽

Wide Energy ◽

High Energy Emission

AbstractCritical progress in our understanding of high energy emission from AGN has been determined in the last 10 years by X-ray monitoring campaigns with many space missions, notably ROSAT, ASCA, RXTE, BeppoSAX, and XMM, often in conjunction with observations at other frequencies. The emphasis of the present review is on recent findings about X-ray variability of blazars. Among AGN, these exhibit the largest amplitude variations of the X-ray emission, often well correlated with variations at higher energies (GeV and TeV radiation). The accurate sampling of the X-ray spectra over more than three decades in energy, made possible by the wide energy range of BeppoSAX, has also shown strong spectral variability in blazar active states, suggesting extreme electron energies and leading to the identification of a class of ‘extreme synchrotron’ sources.

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