Experimental study of β and β−n decay of the neutron-rich N=54 isotone 87As

Abstract

The β-decay properties of neutron-rich 87As produced in the proton-induced fission of 238U were studied at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The low-energy excited states in N=53 87Se and N=52 86Se were identified through β−γ and β-delayed neutron-γ decay of 87As, respectively. The experimental systematics of low-energy levels of N=53 isotones, Z=34 87Se, and Z=32 85Ge, and along with an analysis of shell-model calculations, allow us to discuss the main features of excited states expected for the next N=53 isotone, 83Zn.