Lifetimes of Cascade-Free Transitions in Ions of Ar, Cl, and S

Abstract

Radiative lifetimes of vacuum uv multiplets classified as ($3s^{2}3p^m-3s3\mathrm{}{p}^{m+1\mathrm{}}$) in Ar II, Ar III, Ar IV, S II, and Cl II, measured with a pulsed-electron technique, are found to be cascade free with lifetimes 13 to 55 times larger than given by central-field calculations. The discrepancy is attributed to configuration mixing with terms of the $3s3p^{m-1\mathrm{}}3d$ configurations.