A new extra-focus monochromator designed for high-performance VUV beamlines

2015 ◽  
Vol 22 (2) ◽  
pp. 328-335 ◽  
Author(s):  
Chaofan Xue ◽  
Yanqing Wu ◽  
Ying Zou ◽  
Lian Xue ◽  
Yong Wang ◽  
...  

A new monochromator called an extra-focus constant-included-angle varied-line-spacing (VLS) cylindrical-grating monochromator (extra-focus CIA-VCGM) is described. This monochromator is based on the Hettrick–Underwood scheme where the plane VLS grating is replaced by a cylindrical one in order to zero the defocus at three reference photon energies in the vacuum-ultraviolet range. It has a simple mechanical structure and a fixed focus spot with high performance over a wide energy range. Furthermore, its mechanical compatibility with a standard VLS plane-grating monochromator allows convenient extension into the soft-X-ray range.

2015 ◽  
Vol 22 (6) ◽  
pp. 1353-1358 ◽  
Author(s):  
Chaofan Xue ◽  
Yanqing Wu ◽  
Ying Zou ◽  
Lian Xue ◽  
Zhi Guo ◽  
...  

A new monochromator scheme is presented in which an extra-focus constant-included-angle varied-line-spacing cylindrical-grating monochromator (extra-focus CIA-VCGM) is conveniently combined with a variable-included-angle varied-line-spacing plane-grating monochromator (VIA-VPGM). This dual-mode solution delivers high performance in the energy range from vacuum ultraviolet (VUV) to soft X-ray. The resolving power and the efficiency of this dual-mode grating monochromator are analyzed in detail based on realistic parameters. Comparisons with the commonly used variable-included-angle plane-grating monochromator and normal-incidence monochromator (VIA-PGM/NIM) hybrid monochromator are made.


2013 ◽  
Vol 21 (1) ◽  
pp. 273-279 ◽  
Author(s):  
L. Xue ◽  
R. Reininger ◽  
Y.-Q. Wu ◽  
Y. Zou ◽  
Z.-M. Xu ◽  
...  

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.


1998 ◽  
Vol 5 (3) ◽  
pp. 246-251 ◽  
Author(s):  
Yonglian Yan ◽  
Eiji Shigemasa ◽  
Akira Yagishita

The design and experimental evaluation of a high-resolution varied-line-spacing-grating monochromator constructed at the Photon Factory are described. Various applications of a varied-line-spacing grating in a high-performance soft X-ray monochromator are discussed.


1998 ◽  
Vol 5 (3) ◽  
pp. 989-991 ◽  
Author(s):  
Andrei Rogalev ◽  
Vincent Gotte ◽  
Jose´ Goulon ◽  
Christophe Gauthier ◽  
Joel Chavanne ◽  
...  

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.


1996 ◽  
Vol 165 ◽  
pp. 321-331
Author(s):  
H. Inoue

ASCA, the fourth Japanese X-ray astronomy satellite, was launched by the Institute of Space and Astronautical Science (ISAS) on 1993 February 20. ASCA is designed to be a high-capability X-ray observatory (Tanaka et al. 1994). It is equipped with nested thin-foil mirrors which provide a large effective area over a wide energy range from 0.5 to 10 keV. Two different types of detectors, CCD cameras (SIS) and imaging gas scintillation proportional counters (GIS) are employed as the focal plane instruments.


2010 ◽  
Author(s):  
Kenta Amemiya ◽  
Akio Toyoshima ◽  
Takashi Kikuchi ◽  
Takashi Kosuge ◽  
Kazuyuki Nigorikawa ◽  
...  

2020 ◽  
Vol 27 (2) ◽  
pp. 455-461
Author(s):  
Makoto Hirose ◽  
Kei Shimomura ◽  
Takaya Higashino ◽  
Nozomu Ishiguro ◽  
Yukio Takahashi

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.


Author(s):  
David C. Joy

High resolution scanning electron microscopy is still a relatively new and unfamiliar concept because in the early days of the SEM it was expected, that secondary electron imaging would be limited to a resolution of between 5 and 10nm at best. Now, however, because of improvements in instrumentation and technique based on advances in the understanding of electron beam interactions with solids current SEMs can demonstrate spatial resolutions below 1nm, rivaling those obtained by transmission instruments.High performance scanning electron microscopes always incorporate two advanced items of instrumentation. Firstly they use field emission guns (FEGs). The high brightness, low energy spread, and small source size of the FEG makes it possible to produce an electron probe of sub-nanometer size which contains sufficient current for secondary electron imaging (i.e 10-12 amps or more) and which can maintain this performance over a wide energy range (3 to 30keV). Secondly, the new high performance instruments place the specimen within a high excitation, immersion, probe forming lens.


2005 ◽  
Vol 44 (7B) ◽  
pp. 5500-5504 ◽  
Author(s):  
Yuichi Utsumi ◽  
Takefumi Kishimoto ◽  
Tadashi Hattori ◽  
Hirotsugu Hara

1996 ◽  
Vol 160 ◽  
pp. 367-374 ◽  
Author(s):  
Nobuyuki Kawai ◽  
Keisuke Tamura

AbstractResults from the X-ray observations of pulsars with ASCA are presented. The surroundings of pulsars are investigated in detail taking advantage of ASCA’s unique capabilities; high spectral resolution and a high throughput over a wide energy range from 0.4 keV to 10 keV. The spectral characteristics of the nebulae of PSR B1509—58 and the Vela pulsar are spectroscopically investigated. A jet-like feature is found from PSR B1509—58. We detected diffuse emission sources in the vicinity of many pulsars. The high probability of finding such diffuse sources for many pulsars suggests that they exist universally for all the active pulsars, and that they are powered by the pulsars. SNR Kes 32 was imaged in X-ray for the first time. Its X-ray properties can be used to examine its association with the nearby pulsar PSR B1610—50.


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