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

Abstract

Excited states of ${}^{129}$In populated following the ${\hat{I}}^2$-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). ${\hat{I}}^2$- and ${\hat{I}}^3$-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 ${\hat{I}}^2$-particles were detected with SCEPTAR. From the ${\hat{I}}^2$-${\hat{I}}^3$-${\hat{I}}^3$ 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 ${\hat{I}}^2$-feeding intensities suggest that some of the high-lying states were populated by the $\hat{I}½0g_{7/2}\to \ddot{I}€0g_{9/2}$ 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.

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