$\beta$ decay of semi-magic ${}^{130}\mathrm{Cd}$: Revision and extension of the level scheme of ${}^{130}\mathrm{In}$

The $\beta$ decay of the semi-magic nucleus ${}^{130}\mathrm{Cd}$ has been studied at the RIBF facility at the RIKEN Nishina Center. The high statistics of the present experiment allowed for a revision of the established level scheme of ${}^{130}\mathrm{In}$ and the observation of additional $\beta$ feeding to high-lying core-excited states in ${}^{130}\mathrm{In}$. The experimental results are compared to shell-model calculations employing a model space consisting of the full major $N=50–82$ neutron and $Z=28–50$ proton shells and the NA-14 interaction, and good agreement is found.

Figure 1

$\gamma$-ray spectrum observed in prompt coincidence with the first $\beta$ decay detected in WAS3ABi within 381 ms $\left(=3T_{1/2}\right)$ after the implantation of a ${}^{130}\mathrm{Cd}$ ion and requiring that the implantation and the decay occurred in the same DSSSD and with a maximum position difference of 1 mm in the horizontal and vertical directions. The most intense lines are labeled by their energies. Known transitions in ${}^{130}\mathrm{Sn}$, populated following the ${}^{130}\mathrm{In}$ daughter decay, are labeled by a “$\#$”, while the symbol “$\&$” marks the most intense $\gamma$ ray emitted in the decay of the strongest reaction channel ${}^{132}\mathrm{In}$ and falsely correlated to ${}^{130}\mathrm{Cd}$. Single-escape peaks are labeled by SE.

Figure 2

Spectrum of $\gamma$ rays observed in prompt coincidence with (a) the 499 keV, (b) the 2805 keV, and (c) the 2739 keV transition emitted following the first or second decay detected in WAS3ABi within 381 ms after the implantation of a ${}^{130}\mathrm{Cd}$ ion.

Figure 3

Spectrum of $\gamma$ rays observed in coincidence with (a) the 388 keV and (b) the 451 keV transition emitted after the first or second decay detected in WAS3ABi within 381 ms after the implantation of a ${}^{130}\mathrm{Cd}$ ion. In case (a) no prompt time gate was applied to account for the isomeric character of the 388 keV state.

Figure 4

Proposed level scheme of ${}^{130}\mathrm{In}$ established based on the coincidence relations between the $\gamma$ rays emitted following the $\beta$ decay of ${}^{130}\mathrm{Cd}$. Tentatively placed $\gamma$ rays are shown as thin lines.

Figure 5

Comparison of the low-energy part of the experimental level scheme of ${}^{130}\mathrm{In}$ with shell-model calculations (see text for details). The grey areas indicate the experimental uncertainties of the positions of the $\left({10}^{-}\right)$ and $\left(5^{+}\right)$ states.