The electron-excitation, phase-shift method of Lawrence has been applied to the determination of radiative lifetimes of Ar II transitions. The measured levels, which are primarily those of 4<i>p</i><sup>2</sup><i>S</i>, <sup>2</sup><i>P</i>, <sup>4</sup><i>D</i>, were studied using transitions in the region from 1900–4500 Å. The Ar II lifetimes measured ranged from 1.2 to 10.6 nsec and involve a number of levels in which configuration interaction is present.
TERRY A. MATILSKY and JAMES E. HESSER, "Radiative Lifetimes of Ultraviolet Transitions of Argon II," J. Opt. Soc. Am. 59, 579-582 (1969)