Half-lives of neutron-rich ${}^{128-130}$Cd

Abstract

The ${\hat{I}}^2$-decay half-lives of ${}^{128\text{–}130}$Cd have been measured with the newly commissioned GRIFFIN ${\hat{I}}^3$-ray spectrometer at the TRIUMF-ISAC facility. The time structures of the most intense ${\hat{I}}^3$-rays emitted following the ${\hat{I}}^2$-decay were used to determine the half-lives of ${}^{128}$Cd and ${}^{130}$Cd to be $T_{1/2}=246.2(21)$ ms and $T_{1/2}=126(4)$ ms, respectively. The half-lives of the 3/2${}^{+}$ and 11/2${}^{-}$ states of ${}^{129}$Cd were measured to be $T_{1/2}(3/2^{+})=157(8)$ ms and $T_{1/2}(11/2^{-})=147(3)$ ms. The half-lives of the Cd isotopes around the $N=82$ shell closure are an important ingredient in astrophysical simulations to derive the magnitude of the second $r$-process abundance peak in the $A\sim 130$ region. Our new results are compared with recent literature values and theoretical calculations.