Proton spectroscopy beyond the drip line near<i>A</i>=150

Abstract

The Daresbury recoil separator has been used to measure proton radioactivity from the nuclei $^{150}\mathrm{Lu}$, $^{151}\mathrm{Lu}$, and $^{147}\mathrm{Tm}$, produced using the reactions $^{58}\mathrm{Ni}$${+}^{96}$Ru${\ensuremath{\rightarrow}}^{154}$${\mathrm{Hf}}^{\mathrm{*}}$ and $^{58}\mathrm{Ni}$${+}^{92}$Mo${\ensuremath{\rightarrow}}^{150}$${\mathrm{Yb}}^{\mathrm{*}}$. The half-life of $^{150}\mathrm{Lu}$ has been measured for the first time as 35\ifmmode\pm\else\textpm\fi{}10 ms, which identifies the proton decay as an l=5 transition from the ${\mathit{h}}_{11/2}$ proton state. New half-life and energy measurements have been made for the known proton transitions from $^{147}\mathrm{Tm}$ and $^{151}\mathrm{Lu}$, which have been unambiguously assigned using the direct mass identification of the recoil separator. A new half-life measurement of the proton emitter $^{109}\mathrm{I}$ is also reported.