Decay of 152Pm isomers

Abstract

Isomers of 152Pm were observed when enriched 152Sm was bombarded with fast neutrons. Production of the isomers was through the 152Sm ( n, p) 152Pm reaction using 14·8 MeV neutrons. The β- and γ-ray decay of the isomers were studied using an 8-cm 3 Ge(Li) spectrometer and scintillation detectors. Half-lives of the ground and isomeric states were determined to be 3·8±0·5 and 7·55±0·70 min, respectively. The 3·8 min isomer was observed to decay to the ground state, first excited 2 + state, and to the β- and γ-vibrational states of 152Sm. The 7·55 min isomeric state strongly populated a level at 1804·0 keV in 152Sm. A spin-parity of 5 + or 6 + was deduced for the 1804·0 keV level. Tentative decay schemes for the 152Pm isomers are proposed.