Iron concentration measurements on TFTR using charge exchange excited lines of helium-like iron in the 200--700 A region

Charge exchange excited lines of Fe23+ in the EUV region have been observed on the TFTR tokamak. These lines are emitted by Δn=1 transitions between levels with n=6--10 following charge exchange recombination of He-like iron ions (Fe24+) with deuterium atoms injected by neutral beams. Iron concentrations are obtained by modeling the line brightnesses using a beam attenuation code and iron charge exchange cross sections. The results are in good agreement with iron concentrations obtained from impurity transport code modeling of the brightnesses of EUV electron impact excited lines, demonstrating that charge exchange excited lines may be reliably used to measure local metallic impurity concentrations