Spectroscopic studies of neutron-rich in 129 and its β -decay daughter, Sn 129, using the GRIFFIN spectrometer

Abstract

The β decay of neutron-rich In129 into Sn129 was studied using the GRIFFIN spectrometer at the ISAC facility at TRIUMF. The study observed the half-lives of the ground state and each of the β-decaying isomers. The level scheme of Sn129 has been expanded with thirty-one new γ-ray transitions and nine new excited levels, leading to a reevaluation of the β branching ratios and level spin assignments. The observation of the β decay of the (29/2+) 1911-keV isomeric state in In129 is reported for the first time, with a branching ratio of 2.0(5)%.