The $beta$-decay of neutron-rich $^{129}$In into $^{129}$Sn 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 $beta$-decaying isomers. The level scheme of $^{129}$Sn has been expanded with thirty-one new $gamma$-ray transitions and nine new excited levels, leading to a re-evaluation of the $beta$-branching ratios and level spin assignments. The observation of the $beta$-decay of the (29/2$^{+}$) 1911-keV isomeric state in $^{129}$In is reported for the first time, with a branching ratio of 2.0(5)$%$.
Download