Muonic x-ray transition energies have been measured in ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$, ${}_{}{}^{138}{}_{}{}^{}\mathrm{Ba}$, ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}$, ${}_{}{}^{142}{}_{}{}^{}\mathrm{Ce}$, and ${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$ using a high-efficiency Ge(Li) detector. Precise measurements and relative-intensity measurements have made it possible to identify transitions to and from the $2s$ state in each of these targets. There is good agreement between theoretical and experimental relative intensities for these transitions, except for the ${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$ nucleus. These transition energies, together with those from the $2p-1s$, $3d-2p$, and $4d-2p$ transitions are used to deduce sets of nuclear charge parameters. It has been found that for each target except ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$, the best agreement between theory and experiment is obtained by applying the theoretical nuclear polarization corrections to all levels with $n>\mathrm{}1\mathrm{}$, and varying the nuclear polarization induced by the muon in the $1s$ state. The nuclear polarization values determined were 5.8 ± 1.5 keV for ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$, 6.7 ± 1.4 keV for ${}_{}{}^{138}{}_{}{}^{}\mathrm{Ba}$, 6.5 ± 1.3 keV for ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}$, 7.0 ± 1.4 keV for ${}_{}{}^{142}{}_{}{}^{}\mathrm{Ce}$, and 5.5 ± 1.7 keV for ${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$. These results are in fair agreement with the most recent theoretical predictions.

• Received 2 October 1972

DOI:https://doi.org/10.1103/PhysRevC.8.2453