Measurement of theL2-L3Coster-Kronig transition probability in Pb (Z=82)

The value of the $L_2$-$L_3$ Coster-Kronig transition probability ($f_{23}$) in Pb has been determined by multiparameter K versus L x-ray coincidence measurements using high-energy-resolution germanium and silicon detectors. The Pb x rays were obtained from a radioactive source of ${}_{}{}^{207}{}_{}{}^{}\mathrm{Bi}$. A new method of data analysis to determine the contribution of K${\alpha }_1$ x rays to the K${\alpha }_2$ x-ray peak is described. Precise determination of this contribution is crucial to accurate measurement of $f_{23}$. The value obtained, $f_{23}$=0.112±0.001, is slightly lower than predicted by the latest theoretical calculations. A trend toward deviations from theory in the same direction appears to be confirmed by recently measured values of $f_{23}$ in other medium- and high-Z atoms.