Relative intensities of $L$ x rays emitted during the radiative decay of $L_2$ and $L_3$ subshell vacancies are investigated by Si(Li) x-ray detectors, over a range of $65\le Z\le 94$. Intensities of transitions involving $N$, $O$,... electrons compared to those involving $M$-shell electrons are found to be slightly underestimated in Scofield's theoretical calculations. $L_1$ subshell yields for $Z=82\mathrm{}$ are measured by a high-resolution study of the Pb $L$-x-ray spectrum from the decay of ${}_{}{}^{207}{}_{}{}^{}\mathrm{Bi}$ with the following results: ${\omega }_1=0.09\mathrm{}\pm 0.02$, $f_{12}=0.17\mathrm{}\pm 0.05$, $f_{13}=0.61\mathrm{}\pm 0.08$, and $s_1=0.353\mathrm{}\pm 0.053$.

• Received 8 September 1970

DOI:https://doi.org/10.1103/PhysRevA.3.1568