Doppler profile diagnostics on VUV spectra for the impurity ion temperature in edge plasmas of Large Helical Device

Abstract

A space-resolved VUV spectroscopy using a 3 m normal incidence spectrometer is utilized to measure the impurity emission profile in the edge and divertor plasmas of the Large Helical Device in the wavelength range of 300 - 3200 Å. The ion temperatures derived from the Doppler profile fitting for the spectra of carbon CII 1335.71 × 2 Å, CIII 977.02 × 2 Å, and CIV 1548.20 × 2 Å are comparable to ionization potential for each charge state. The vertical profile of the ion temperature measured from CIV line has higher values in the edge observation chords compared to those in the central chords.