Decay ofEr150

A new activity, $T_{\frac{1}{2}}=20\mathrm{}\pm 2$ sec, was observed in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ bombardments of ${}_{}{}^{144}{}_{}{}^{}\mathrm{Sm}$. Only one $\gamma$ ray, 476.0±0.1 keV, was found to be associated with this nuclide. We identify the new isotope as ${}_{}{}^{150}{}_{}{}^{}\mathrm{Er}$ and propose that it decays mainly to one level in ${}_{}{}^{150}{}_{}{}^{}\mathrm{Ho}$ at an excitation energy of ∼476 keV by an allowed $\beta$ transition which connects states with the following configurations: $0^{+}(\pi h_{\frac{11}{2}}, \pi h_{\frac{11}{2}})\to 1^{+}(\pi h_{\frac{11}{2}}, \nu h_{\frac{9}{2}})$. As part of the investigation, the decay properties of the high- and low-spin ${}_{}{}^{150}{}_{}{}^{}\mathrm{Ho}$ isomers were reexamined.