Experimental study of theβ-delayed proton decays ofEr145,147

Abstract

The $\ensuremath{\beta}$-delayed proton decays of $^{145,147}\mathrm{Er}$ have been studied experimentally using the $^{58}\mathrm{Ni}+^{92}\mathrm{Mo}$ reaction at beam energy of $383$ MeV. On the basis of a He-jet apparatus coupled with a tape transport system, the $\ensuremath{\beta}$-delayed proton radioactivities both from the $\ensuremath{\nu}{s}_{1/2}$ ground state and the $\ensuremath{\nu}{h}_{11/2}$ isomer in $^{145,147}\mathrm{Er}$ were observed by proton-$\ensuremath{\gamma}$ coincidence measurements. By analyzing the time distributions of the $4$${}^{+}\ensuremath{\rightarrow}{2}^{+}\ensuremath{\gamma}$ transitions in the granddaughter nuclei $^{144,146}\mathrm{Dy}$, the half-lives of $1.0\ifmmode\pm\else\textpm\fi{}0.3$ s and $1.6\ifmmode\pm\else\textpm\fi{}0.2$ s have been deduced for the $\ensuremath{\nu}{h}_{11/2}$ isomers in $^{145,147}\mathrm{Er}$, respectively.