Mean lives of four electronically excited atomic levels in Ar I have been determined using a method of delayed coincidence. The measured values of the mean lives of the 2<i>p</i><sub>1</sub> through 2<i>p</i><sub>4</sub> (Paschen notation) levels in neutral argon determined from transitions with associated wavelengths extending from 6677 to 7147 Å are as follows: 2<i>p</i><sub>1</sub>, 21±2 nsec; 2<i>p</i><sub>2</sub>, 25±1 nsec; 2<i>P</i><sub>3</sub>, 26±1 nsec, and 2<i>p</i><sub>4</sub>, 31±2 nsec. The lifetimes were estimated to contain systematic errors varying from 5% to 15% and are presented in comparison With results of other workers.
JULES Z. KLOSE, "Lifetimes of Some 4p Levels in Argon I," J. Opt. Soc. Am. 57, 1242-1244 (1967)