KSTAR Charge Exchange Spectroscopy system

Abstract

The Charge Exchange Spectroscopy (CES) system for the Korea Superconducting Tokamak Advanced Research (KSTAR) device is designed to get profiles of the ion temperature, poloidal and toroidal rotation, and impurity density by using modulated Neutral Beam Injection (NBI). The CES diagnostic will measure the ion temperature of carbon and other impurities, in conjunction with the neutral heating beam in KSTAR. The visible light from the plasma would be collected via a collection optics assembly and imaged onto quartz fibers. We show the progress of the KSTAR CES diagnostic including the collection assembly, lens design, and cassette system and compare the KSTAR CES system design with the designs of other international tokamaks. The KSTAR CES system utilizes a 1.33 m Czerny-Turner spectrometer with variable wavelength. The detector is a thinned back-illuminated Charge Coupled Device (CCD) that has high quantum efficiency and a high readout speed. The spectrometer and CCD detector which will be used in the KSTAR CES system have been tested and several visible lines have been measured in a helium discharge.