Experimental Lifetimes of the 5p Levels in Argon i*

Mean lives of 7 of the 10 5p atomic levels in Ar i have been determined using electronic excitation and a method of delayed coincidence. The measured values, in nanoseconds, of the mean lives of the 3p1 and 3p5 through 3p10 levels (Paschen notation) in neutral argon are: 3p1, 71±2; 3p5, 95±2; 3p6, 124±3; 3p7, 149±3; 3p8, 166±5; 3p9, 141±2; and 3p10, 189±3. The error given with each lifetime is the standard deviation in the mean as evaluated from the dispersion of the individual measurements. Wavelengths used in the determinations ranged from 4159 to 4702 Å. The lifetimes were estimated to contain systematic errors varying from 5% to 15% and are presented in comparison with values obtained by combining theoretical calculations with other experimental results.