A soft X-ray (80–1500 eV) grazing-incidence monochromator with varied-line-spacing plane gratings at PF-BL-11A

1998 ◽  
Vol 5 (3) ◽  
pp. 729-731 ◽  
Author(s):  
Yoshinori Kitajima ◽  
Kenta Amemiya ◽  
Yoshiki Yonamoto ◽  
Toshiaki Ohta ◽  
Takashi Kikuchi ◽  
...  

The design and performance of a new soft X-ray beamline BL-11A at the Photon Factory (PF) are presented. A Hettrick-type grazing-incidence monochromator equipped with three varied-line-spacing plane gratings was designed and constructed at a bending-magnet source of the PF 2.5 GeV storage ring. An 800 lines mm−1 laminar grating produced by aspheric-wavefront holographic recording optics, as well as a mechanically ruled blazed one, were tested. A resolving power of more than 4500 was achieved at 400 eV with either grating, and ∼1010 photons s−1 are available at a resolving power of 2000. High photon flux enables low-concentration samples, such as surface adsorbates, to be studied. A simple scanning mechanism for a wide energy range is quite useful for EXAFS measurements on light elements such as C, N and O.

2020 ◽  
Vol 27 (4) ◽  
pp. 870-882
Author(s):  
Ximing Zhang ◽  
Zhi Guo ◽  
Xiangyu Meng ◽  
Jiahua Chen ◽  
Zhan Ji ◽  
...  

A self-amplified spontaneous emission free-electron laser (FEL) is under construction at the Shanghai Soft X-ray Free-Electron Facility. Therefore, it is necessary to develop a suitable diagnostic tool capable of resolving the natural emission band of each FEL pulse. Thus, an online spectrometer with a plane mirror and plane variable-line-spacing grating at grazing incidence to monitor each single FEL pulse during the propagation of FEL radiation has been designed and is presented in this work. The method of ray tracing is used for monitoring incident radiation in order to understand spectral characteristics, and SHADOW, an X-ray optics simulation tool, and SRW, an X-ray optics wavefront tool, are applied to study the resolving power and focusing properties of the grating. The designed resolving power is ∼3 × 104 at 620 eV. Meanwhile, the effect of the actual slope error of mirrors on the ray-tracing results is also discussed. In order to provide further optimization for the choice of grating, a comparison of resolving powers between 2000 lines mm−1 and 3000 lines mm−1 gratings at different energies is analyzed in detail and radiation damage of mirrors as well as parameters such as the first-order diffraction angle β, the exit-arm length r 2, and the tilt angle θ between the focal plane and the diffraction arm are studied and optimized. This work has provided comprehensive designing methods and detailed data for the design of diagnostic spectrometers in soft X-ray FELs and will be favorable to the design of other similar instruments.


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.


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.


2013 ◽  
Vol 46 (6) ◽  
pp. 1544-1550 ◽  
Author(s):  
Matej Jergel ◽  
Peter Šiffalovič ◽  
Karol Végsö ◽  
Eva Majková ◽  
Dušan Korytár ◽  
...  

The application of V-shaped channel-cut GeSi(220) and Ge(220) monochromators for one-dimensional extreme X-ray beam compression was tested on a table-top setup for grazing-incidence small-angle X-ray scattering (GISAXS) with a microfocus source. A lattice constant gradient and different asymmetry angles of the diffractors were employed to enhance the compression factor to 21 and 15, respectively. It was demonstrated that the output beam parameters in terms of the size, divergence, photon flux and spectral bandwidth surpass those of the slit collimators used traditionally in GISAXS. A beam size far below 100 µm allows a high-resolution spatial GISAXS mapping, while the reciprocal space resolution of ∼500 nm approaches the level of synchrotron measurements and allows a fast one-shot detection of high-resolution GISAXS patterns. An oversampling shifts the detection limit up to ∼1 µm. The very short design of the compact high-resolution table-top GISAXS setup is another advantage of the extreme beam compression. Benefits of V-shaped monochromators for medium-resolution X-ray diffraction experiments as a bonus application are demonstrated by a comparison with parallel channel-cut monochromators combined with a slit.


1998 ◽  
Vol 5 (3) ◽  
pp. 536-538 ◽  
Author(s):  
Takeshi Nakatani ◽  
Yuji Saitoh ◽  
Yuden Teraoka ◽  
Tetsuo Okane ◽  
Akinari Yokoya

An undulator beamline for spectroscopy studies focusing on the electronic structure of actinide materials is under construction. Linearly or circularly polarized soft X-rays are provided by employing a variably polarizing undulator. Varied-line-spacing plane gratings and a sagittal-focusing system are used to monochromatize the undulator beam, whose energy ranges from 0.3 to 1.5 keV. A resolving power of 104 is expected in the whole energy region. These components are methodically operated by the SPring-8 beamline control system. There are three experimental stations in the beamline. In one of the stations the photoemission spectroscopy experiments are carried out at a radioisotope-controlled area where actinide compounds as well as unsealed radioactive materials are usable. Other experimental stations are planned in the beamline for surface photochemical reactions and biological applications.


2014 ◽  
Vol 03 (02) ◽  
pp. 1440008 ◽  
Author(s):  
M. Beilicke ◽  
F. Kislat ◽  
A. Zajczyk ◽  
Q. Guo ◽  
R. Endsley ◽  
...  

X-ray polarimetry promises to give qualitatively new information about high-energy astrophysical sources, such as binary black hole systems, micro-quasars, active galactic nuclei, neutron stars, and gamma-ray bursts. We designed, built and tested a X-ray polarimeter, X-Calibur, to be used in the focal plane of the balloon-borne InFOCμS grazing incidence X-ray telescope. X-Calibur combines a low-Z scatterer with a Cadmium Zinc Telluride (CZT) detector assembly to measure the polarization of 20–80 keV X-rays making use of the fact that polarized photons scatter preferentially perpendicular to the electric field orientation. X-Calibur achieves a high detection efficiency of ≃80%. The X-Calibur detector assembly is completed, tested, and fully calibrated. The response to a polarized X-ray beam was measured successfully at the Cornell High Energy Synchrotron Source. This paper describes the design, calibration and performance of the X-Calibur polarimeter. In principle, a similar space-borne scattering polarimeter could operate over the broader 2–100 keV energy band.


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.


2002 ◽  
Vol 35 (1) ◽  
pp. 41-48 ◽  
Author(s):  
M. Servidori

A two-germanium-crystal four-220-reflection (+ - - \,+) monochromator, combining high intensity with high resolution, is proposed in this work. The main characteristic is that only the first reflection is asymmetric. The asymmetry factor was chosen so as to allow mixing of asymmetric and symmetric reflections in a monolithic channel-cut crystal without the need for rotation of the two monolith components to correct for the different refraction-induced angular shifts of the reflection pair. It is demonstrated that the exit-beam divergence in the diffraction plane and the fractional wavelength band-pass are smaller by 40% than those of the widely used germanium 220 Bartels monochromator, while the photon flux collected from the source is larger by a factor of five. The optical features and performance of the monochromator are discussed and compared with those of other (+ - - \,+) monochromators reported in the literature.


X-ray gratings have been developed for use in the wavelength region of 0.01-20 nm, where it is required to employ a grazing incidence configuration. The gratings have a rectangular profile and radiation is diffracted both from the tops and bottoms of the grooves. They therefore differ from blazed gratings, used at grazing incidence, in that a substantial portion of the grating participates in the diffraction process. A scalar diffraction theory has been developed which demonstrates that grating diffraction efficiency varies periodically with wavelength, pitch, groove depth and incidence angle. The theory can be used to optimize grating parameters for most efficient use in any selected region of the spectrum. The gratings are produced by processing a ruled 300 lines per millimetre master grating, so that surface profile defects introduced by ruling are eliminated. Grating performance has been assessed by means of a specially designed grating analyser in addition to spectrometers and a spectrograph. The experimental results are in qualitative agreement with theory. At very short wavelengths of 0.05 nm and grazing incidence angles of about 5', the diffraction efficiency in the first order is below 1 %. The efficiency rises rapidly to between 5 and 10 % at 0.15 nm and to 20 % in the 1 nm region where the incidence angles are typically a few degrees.


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