Decay Spectroscopy of ${}^{129}$Cd

Abstract

Excited states of ${}^{129}$In populated following the $\beta$-decay of ${}^{129}$Cd were experimentally studied with the GRIFFIN spectrometer at the ISAC facility of TRIUMF, Canada. A 480-MeV proton beam was impinged on a uranium carbide target and ${}^{129}$Cd was extracted using the Ion Guide Laser Ion Source (IG-LIS). $\beta$- and $\gamma$-rays following the decay of ${}^{129}$Cd were detected with the GRIFFIN spectrometer comprising the plastic scintillator SCEPTAR and 16 high-purity germanium (HPGe) clover-type detectors. %, along with the $\beta$-particles were detected with SCEPTAR. From the $\beta$-$\gamma$-$\gamma$ coincidence analysis, 32 new transitions and 7 new excited states were established, expanding the previously known level scheme of ${}^{129}$In. The $\log ft$ values deduced from the $\beta$-feeding intensities suggest that some of the high-lying states were populated by the $\nu 0g_{7/2}\to \pi 0g_{9/2}$ allowed Gamow-Teller (GT) transition, which indicates that the allowed GT transition is more dominant in the ${}^{129}$Cd decay than previously reported. Observation of fragmented Gamow-Teller strengths is consistent with theoretical calculations.

Comments: 13 pages, 9 figures, to be published in Physical Review C