Spectroscopy ofGd153andGd157using the(p,dγ)reaction

Abstract

Low-spin single quasineutron levels in $^{153}\mathrm{Gd}$ and $^{157}\mathrm{Gd}$ have been studied following the $^{154}\mathrm{Gd}$($p,d\ensuremath{-}\ensuremath{\gamma}$)$^{153}\mathrm{Gd}$ and $^{158}\mathrm{Gd}$($p,d\ensuremath{-}\ensuremath{\gamma}$)$^{157}\mathrm{Gd}$ reactions. A combined Si telescope and high-purity germanium array was utilized, allowing $d\text{\ensuremath{-}}\ensuremath{\gamma}$ and $d\text{\ensuremath{-}}\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}$ coincidence measurements. Almost all of the established low-excitation-energy, low-spin structures were confirmed in both $^{153}\mathrm{Gd}$ and $^{157}\mathrm{Gd}$. Several new levels and numerous new $\ensuremath{\gamma}$ rays are observed in both nuclei, particularly for ${E}_{x}\ensuremath{\ge}1$ MeV. Residual effects of a neutron subshell closure at $N=64$ are observed in the form of a large excitation energy gap in the single quasineutron level schemes.