Half-life measurement of ^133mCe with $\gamma$ -spectrometry

Abstract.

In this paper we describe our experiment determining the half-life of ^133mCe . An activation-based nuclear-reaction cross-section measurement has been carried out for the ¹³⁰Ba($\alpha$, n)^133mCe reaction, in order to improve our knowledge of the astrophysical p-process. For the analysis of such a measurement, the precise knowledge of the decay half-life of the reaction product is desired. In the case of ^133mCe the literature half-life value has only been known with a high relative uncertainty. A measurement utilizing $\gamma$ -spectrometry has been carried out to refine the half-life of ^133mCe . As a result, the new recommended half-life is t _1/2 = (5.326±0.011) h. This value has been found to be consistent with the previous literature value, while its uncertainty has been reduced by more than a factor of 30.