Determination of Ion Temperature Distributions from Doppler Broadenings of Impurity Lines in the Vacuum UV Region for Tokamak Discharges

Doppler broadenings of impurity (O, N and C) lines in hydrogen discharges were observed with the JFT-2 and DIVA tokamak devices for the purpose of determining the spatial distribution of the ion temperature. A 1-meter Czerny-Turner type vacuum monochromator was used in higher orders for sufficient resolution. Impurity emissions are localized in shell-like regions in the minor cross-section. The radial distribution of the ion temperature was determined from the Doppler broadening of various impurity lines and from the localization of line intensities. The Doppler temperatures of the 0⁺⁶ ion were found to be 256 eV for a 100 kA, 14 kG discharge with JFT-2 and 220 eV for a 28 kA, 20 kG discharge with DIVA.