Levels ofSe84from theSe82(t,p)Se84reaction

The levels of ${}_{}{}^{84}{}_{}{}^{}\mathrm{Se}$ have been investigated by the ${}_{}{}^{82}{}_{}{}^{}\mathrm{Se}\mathrm{}(t,p)\mathrm{}$ reaction with 15-MeV tritons. Proton spectra were recorded with a semiconductor counter telescope at lab angles between 12.5 and 90°. Differential cross sections were measured for 19 levels up to 5.633 MeV and compared with distorted-wave Born-approximation angular distributions. The first excited state in ${}_{}{}^{84}{}_{}{}^{}\mathrm{Se}$ occurs at 1.455 MeV. Excited $0^{+}$ states were observed at 2.247 and 2.655 MeV, with cross sections equal to that for the ground state. The two-neutron separation energy of ${}_{}{}^{84}{}_{}{}^{}\mathrm{Se}$ was determined to be $S_{2n}=14.498\mathrm{}\pm 0.015$ MeV. Eight excited states of ${}_{}{}^{82}{}_{}{}^{}\mathrm{Se}$ were observed by the ${}_{}{}^{80}{}_{}{}^{}\mathrm{Se}\mathrm{}(t,p)\mathrm{}$ reaction.