The intensities of the $\gamma$ rays (444.1-, 563.9-, 656.1-, 688.0-, and 810.5-keV) between the various levels of the $\beta$-vibrational band and the ground-state rotational band of ${}_{}{}^{152}{}_{}{}^{}\mathrm{Sm}$ are measured from an analysis of high-resolution (2.6-keV) $\gamma$-ray spectra of the 98%-enriched 12.4-yr ${}_{}{}^{152}{}_{}{}^{}\mathrm{Eu}$ decay. Upper limits of the intensities of the ${4_{\beta }}^{+}\to 6^{+}$ and ${4_{\beta }}^{+}\to 2^{+}$ transitions are also given. From the ${\alpha }_k$ of the 444.1-keV transition, the ${2_{\beta }}^{+}\to 4^{+}$ branching is shown to be less than 5% of the total 444.1-keV $\gamma$ intensity. A small but definite broadening of the 810.5-keV photopeak is observed. From these observations it is concluded that the reported $B\mathrm{}\left(E2\mathrm{}\right)\mathrm{}$ ratios for these transitions may have to be changed considerably.

• Received 16 January 1969

DOI:https://doi.org/10.1103/PhysRev.182.1265