Decay Spectroscopy of Neutron-rich ¹²⁹Cd with the GRIFFIN Spectrometer

Nuclei around doubly magic ¹³²Sn are of particular interest in nuclear structure as well as nuclear astrophysics. Their properties provide important input for the r-process as waiting-point nuclei. For example, their shell structures and half-lives affect the shape of the second r-process abundance peak at A∼130. In terms of nuclear structure, the evolution of single-particle levels near shell closures is ideal for testing the current nuclear models far from stability.

There have been two studies on ¹²⁹Cd, however, the level schemes of ¹²⁹In have large discrepancies [1,2]. Also, many of the spins of the excited states remain unclear. Therefore, the main purpose of the present study is to resolve the disagreements in the reported level schemes and to determine the properties of the energy states.

The experiment was performed at the ISAC facility of TRIUMF, Canada. The data was collected with the GRIFFIN spectrometer, along with the β-particle detector SCEPTAR. The high statistics and the high sensitivity of the detectors allowed us to perform a detailed and precise spectroscopy. The results of the analysis, including 29 new transitions and 5 new excited states, will be discussed.

[1] Acta Phys. Pol. B 40, 437 (2009). [2] PRC 91, 054324 (2015).