Lifetimes and Oscillator Strengths for theP1∘3Atomic States of Pb and Sn

Abstract

The zero-field level-crossing (Hanle) technique has been used to measure the mean lives of the ${}_{}{}^3{}_{}{}^{}{P}_1_{}^{\circ }{}_{}{}^{}$ excited states of atomic tin and lead. The results are ${\tau }_{\mathrm{Pb}}=(5.58\mathrm{}\pm 0.72)\times {10}^{-9\mathrm{}}$ sec and ${\tau }_{\mathrm{Sn}}=(4.84\mathrm{}\pm 0.26)\times {10}^{-9\mathrm{}}$ 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 ${}_{}{}^3{}_{}{}^{}{P}_1_{}^{\circ }{}_{}{}^{}$ state of lead as $f_0\left(2833\mathrm{} \mathrm{\AA }\right)=0.197\mathrm{}\pm 0.030$, $f_1\left(3640\mathrm{} \mathrm{\AA }\right)=0.059\mathrm{}\pm 0.010$, $f_2\left(4058\mathrm{} \mathrm{\AA }\right)=0.142\mathrm{}\pm 0.025$; and for the four important decay branches in tin as $f_0\left(2863\mathrm{} \mathrm{\AA }\right)=0.186\mathrm{}\pm 0.018$, $f_1\left(3009\mathrm{} \mathrm{\AA }\right)=0.048\mathrm{}\pm 0.005$, $f_2\left(3175\mathrm{} \mathrm{\AA }\right)=0.035\mathrm{}\pm 0.003$, and $f_3\left(3801\mathrm{} \mathrm{\AA }\right)=0.035\mathrm{}\pm 0.003$. These results are compared with other absolute measurements, and with theoretical predictions determined by Lawrence's extended Bates-Damgaard technique.