Decay properties ofTm150andEr150

The decay properties of ${}_{}{}^{150}{}_{}{}^{}\mathrm{Tm}$ and ${}_{}{}^{150}{}_{}{}^{}\mathrm{Er}$ (produced in ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$ bombardments of ${}_{}{}^{96}{}_{}{}^{}\mathrm{Ru}$) were investigated following on-line mass separation. The half-life of ${}_{}{}^{150}{}_{}{}^{}\mathrm{Tm}$ was measured to be 2.2±0.2 s rather than the value of 3.5 s available in the literature. Based on its decay characteristics, we suggest that this high-spin ${}_{}{}^{150}{}_{}{}^{}\mathrm{Tm}$ isomer has a spin assignment of $6^{\mathrm{-}}$. Among the ${}_{}{}^{150}{}_{}{}^{}\mathrm{Er}$ states fed by this $6^{\mathrm{-}}$ isomer is the yrast $4^{+}$ level (2294.8 keV) which up to now has been observed in neither β-decay nor in-beam γ-ray studies. New transitions observed in ${}_{}{}^{150}{}_{}{}^{}\mathrm{Er}$ decay establish several previously unknown levels in ${}_{}{}^{150}{}_{}{}^{}\mathrm{Ho}$. While the additional γ rays reduce from 100% to 96% the feeding to the 476-keV state in ${}_{}{}^{150}{}_{}{}^{}\mathrm{Ho}$ known earlier, the corresponding logft value is calculated to be 3.6, indicating that this is an allowed, $0^{+}$→$1^{+}$, beta transition. Photon intensities obtained for γ rays following the decay of the ${}_{}{}^{150}{}_{}{}^{}\mathrm{Ho}$ low-spin isomer resolve inconsistent values measured in two previous investigations.