Research and development of x-ray imaging crystal spectrometers for KSTAR

Abstract

The engineering design for two high-resolution x-ray imaging crystal spectrometers for KSTAR tokamak has been completed. A spherically bent quartz crystal and a large area two-dimensional (2D) position-sensitive multiwire proportional counter have been selected for the imaging spectrometers. A prototype 10 cm by 30 cm 2D detector was fabricated and pilot measurement on Alcator C-Mod tokamak was carried out. The final engineering design of the spectrometers and experimental results from the 2D detector are presented.

Investigation of a Novel X-Ray Tube for the Calibration of the X-Ray Crystal Spectrometer in the KSTAR Machine

“…The x-ray crystal spectrometer (XCS) was proposed to measure the x-ray lines from helium like argon Ar XVII in the KSTAR tokamak plasma [2]. Figure 9 shows a horizontal XCS, providing ion and electron temperature profiles, which will be installed at the horizontal midplane of the KSTAR machine.…”

“…Some technical issues in the application of the x-ray tube to the calibration are following : It is required that the 2D detector, the crystal and the x-ray source should be positioned on the Rowland circle in order to expose the best focused x-rays on the detector. To get the line focused x-ray source, a slit with a gap of about 50 µm is positioned in front of the x-ray tube, which experienced in the position calibration using a 55 Fe source in a laboratory [2]. It is essential to investigate the spatial resolution in the detector required for the image measurement.…”

“…A large area two-dimensional position-sensitive detector (10 cm by 30 cm 2D detector) and a spherically bent crystal are used in the KSTAR XCS in order to provide simultaneous x-ray spectra from a number of lines of sight through the plasma. Thus, plasma rotation velocity and the radial profiles of electron and ion temperature can be obtained from the x-ray image by the KSTAR XCS [1]. A novel x-ray tube, which consists of an anode and a line filament as a cathode, was developed for the performance test of the fabricated 2D detector.…”

“…Considerable progress on the research and development of the x-ray crystal spectrometer (XCS) for the KSTAR was done [1][2][3]. A large area two-dimensional position-sensitive detector (10 cm by 30 cm 2D detector) and a spherically bent crystal are used in the KSTAR XCS in order to provide simultaneous x-ray spectra from a number of lines of sight through the plasma.…”

Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas

“…[282][283][284][285] The instrument consists of a spherically bent crystal and a two-dimensional detector, which are arranged in a Johann configuration. The imaging properties of this configuration have been discussed by Bitter et al 252 and Bertschinger et al…”