Half-life determination of 72Ga

Abstract

Gallium-72 is an important Comprehensive Nuclear-Test-Ban Treaty relevant radionuclide that arouses significant interest. However, the reported half-lives of ⁷²Ga are discrepant. In the current work, three solution samples of different concentrations were prepared and sequentially measured by a high-purity Germanium (HPGe) spectrometer. The count rates as a function of time of the 834.1 keV and 630.0 keV γ-lines were followed for the half-life determination. Through mass normalization, the datasets of three samples are combined and the statistical uncertainties are reduced. Half-life values were derived from datasets of each sample and mass normalization and corresponding complete uncertainty budgets are presented. The final half-life determined for ⁷²Ga is 13.94 (2) h, showing a deviation of 1.12% from the last nuclear data sheets (NDS) recommended value. Comparing with the values of previous publications, the result from this work is smaller than most results and consistent with the latest value which has one large uncertainty. A recommended value of 14.07 (3) h is estimated using the power-moderated mean (PMM) method.