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Title: Upgrades of imaging x-ray crystal spectrometers for high-resolution and high-temperature plasma diagnostics on EAST

Upgrade of the imaging X-ray crystal spectrometers continues in order to fulfill the high-performance diagnostics requirements on EAST. For the tangential spectrometer, a new large pixelated two-dimensional detector was deployed on tokamaks for time-resolved X-ray imaging. This vacuum-compatible detector has an area of 83.8 × 325.3 mm{sup 2}, a framing rate over 150 Hz, and water-cooling capability for long-pulse discharges. To effectively extend the temperature limit, a double-crystal assembly was designed to replace the previous single crystals for He-like argon line measurement. The tangential spectrometer employed two crystal slices attached to a common substrate and part of He- and H-like Ar spectra could be recorded on the same detector when crystals were chosen to have similar Bragg angles. This setup cannot only extend the measurable Te up to 10 keV in the core region, but also extend the spatial coverage since He-like argon ions will be present in the outer plasma region. Similarly, crystal slices for He-like iron and argon spectra were adopted on the poloidal spectrometer. Wavelength calibration for absolute rotation velocity measurement will be studied using cadmium characteristic L-shell X-ray lines excited by plasma radiation. A Cd foil is placed before the crystal and can be inserted andmore » retracted for in situ wavelength calibration. The Geant4 code was used to estimate X-ray fluorescence yield and optimize the thickness of the foil.« less
Authors:
; ; ;  [1] ; ; ;  [1] ;  [2] ; ; ; ;  [3] ;  [4] ;  [5] ;  [6] ;  [5]
  1. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)
  2. (China)
  3. Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States)
  4. National Fusion Research Institute, 52 Eoeun-Dong, Yusung-Gu, Daejeon 305-333 (Korea, Republic of)
  5. School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China)
  6. (Korea, Republic of)
Publication Date:
OSTI Identifier:
22308942
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 85; Journal Issue: 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ARGON; ARGON IONS; BRAGG REFLECTION; CADMIUM; CALIBRATION; COOLING; FLUORESCENCE; FOILS; HOT PLASMA; IRON; L SHELL; MONOCRYSTALS; PLASMA DIAGNOSTICS; SPECTRA; THICKNESS; TIME RESOLUTION; TOKAMAK DEVICES; WAVELENGTHS; X-RAY DETECTION; X-RAY SPECTROMETERS