In-beam gamma ray spectroscopy ofRb81

Abstract

The decay schemes of ${}_{}{}^{81}{}_{}{}^{}\mathrm{Rb}$ were studied by $\gamma$-ray spectroscopy with the ${}_{}{}^{79}{}_{}{}^{}\mathrm{Br}(\alpha ,2\mathrm{}n){}_{}{}^{81}{}_{}{}^{}\mathrm{Rb}$ and ${}_{}{}^{68}{}_{}{}^{}\mathrm{Zn}({}_{}{}^{16}{}_{}{}^{}\mathrm{O},p2\mathrm{}n){}_{}{}^{81}{}_{}{}^{}\mathrm{Rb}$ reactions. $\gamma$-singles spectra and $\gamma$-angular distributions were taken. A $\gamma -\gamma$-coincidence measurement was carried out with the ($\alpha ,2\mathrm{}n$) reaction. Twenty four new energy levels were established. A stretched spin band built on the isomeric ${9/2}^{+}$ level at 86 keV and a ${3/2}^{-}$ ground-state quasirotational band were found.