X-ray emission from He-liken=2charge states produced in tokamak plasmas

Measurements of He-like x-ray line spectra for sulfur and chlorine impurity ions in the Alcator-$C$ tokamak plasma are reported. Results are presented on the relative line ratios of the resonance (w), intercombination (x and y), and forbidden (z) lines as well as dielectronic satellite lines for plasma conditions of $T_e=1.0-1.8\mathrm{}$ keV and $N_e=(1.5-7)\mathrm{}\times {10}^{14}$ ${\mathrm{cm}}^{-3\mathrm{}}$. The results are compared with atomic calculations employing accurate atomic data which take into consideration effects on the line ratios due to collisional coupling between the $n=2\mathrm{}$ states involved.