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

Journal Article · Sat Nov 15 00:00:00 EST 2014 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4886387· OSTI ID:22308942

Wang, F. D.; Fu, J.; Li, Y. Y. ^[1]; Pan, X. Y.; Chen, J.; Wan, B. N. ^[1]; Bitter, M.; Hill, K. W.; Delgado-Aparicio, L. F.; Pablant, N. ^[2]; Lee, S. G. ^[3]; Shi, Y. J. ^[4]; Ye, M. Y. ^[4]

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1. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)
2. Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States)
3. National Fusion Research Institute, 52 Eoeun-Dong, Yusung-Gu, Daejeon 305-333 (Korea, Republic of)
4. School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China)

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 and retracted for in situ wavelength calibration. The Geant4 code was used to estimate X-ray fluorescence yield and optimize the thickness of the foil.

• OSTI ID: 22308942
• Journal Information: Review of Scientific Instruments, Vol. 85, Issue 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

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