Beta Decay ofCe146

The $\gamma$-ray spectrum of 14-min ${}_{}{}^{146}{}_{}{}^{}\mathrm{Ce}$ has been reexamined with a high-resolution Ge(Li) detector, and the following previously unreported $\gamma$ transitions were observed: 106.4, 351.9, 369.1, 415.6, 467.9, 491, and 503.0 keV. A previously observed peak at $\approx 99$ keV was resolved into 98.3- and 100.9-keV photopeaks. More precise energies and additional conversion coefficients have been determined for many of the transitions. On the basis of energy differences a new level, believed to be 1+, has been placed at 503.0 keV. $\gamma$-x-ray and $\gamma$-electron coincidence measurements suggest that a previously postulated 35-keV level is de-excited by a 23-12-keV $\gamma$ cascade.