title: Upgrades of imaging x-ray crystal spectrometers for high-resolution and high-temperature plasma diagnostics on EAST.
abstract: 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(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.
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China.
authors.forename: B
authors.initials: B
authors.lastname: Lyu
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China.
authors.forename: F D
authors.initials: FD
authors.lastname: Wang
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China.
authors.forename: X Y
authors.initials: XY
authors.lastname: Pan
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China.
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China.
authors.forename: J
authors.initials: J
authors.lastname: Fu
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Li
authors.affiliation: Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451, USA.
authors.forename: M
authors.initials: M
authors.lastname: Bitter
authors.affiliation: Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451, USA.
authors.forename: K W
authors.initials: KW
authors.lastname: Hill
authors.affiliation: Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451, USA.
authors.forename: L F
authors.initials: LF
authors.lastname: Delgado-Aparicio
authors.affiliation: Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451, USA.
authors.forename: N
authors.initials: N
authors.lastname: Pablant
authors.affiliation: National Fusion Research Institute, 52 Eoeun-Dong, Yusung-Gu, Daejeon 305-333, South Korea.
authors.forename: S G
authors.initials: SG
authors.lastname: Lee
authors.affiliation: School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Shi
authors.affiliation: School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: M Y
authors.initials: MY
authors.lastname: Ye
authors.affiliation: Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, China.
authors.forename: B N
authors.initials: BN
authors.lastname: Wan