LIFETIMES AND OSCILLATOR STRENGTHS FOR 3P1 DEGREES ATOMIC STATES OF PB AND SN

The zero-field level-crossing (Hanle) technique has been used to measure the mean lives of the P1â3 excited states of atomic tin and lead. The results are τPb=(5.58±0.72)×10-9 sec and τSn=(4.84±0.26)×10-9 sec. From these results and branching ratios for transitions to the ground configuration measured by other authors, we have calculated the oscillator strengths for the three important decay branches from the P1â3 state of lead as f0(2833Â A)=0.197±0.030, f1(3640Â A)=0.059±0.010, f2(4058Â A)=0.142±0.025; and for the four important decay branches in tin as f0(2863Â A)=0.186±0.018, f1(3009Â A)=0.048±0.005, f2(3175Â A)=0.035±0.003, and f3(3801Â A)=0.035±0.003. These results are compared with other absolute measurements, and with theoretical predictions determined by Lawrence's extended Bates-Damgaard technique. © 1968 The American Physical Society.