Precise half-life determination of 131Ba and 125Xe.

Barium-131 and Xenon-125 are valuable radioisotopes with numerous scientific and medical applications. We produced both isotopes via proton irradiation of a cesium iodide (CsI) target at the Brookhaven Tandem Van de Graaff accelerator (BTVG). Following irradiation, we conducted systematic γ-ray spectroscopy measurements at the National Nuclear Data Center (NNDC) decay station using a calibrated High-Purity Germanium (HPGe) detector, collecting data over a 2-month period (spanning approximately 4.5 half-lives for 131Ba). Through careful analysis of the characteristic γ-ray emissions from both isotopes, we determined the half-life of 131Ba to be 11.55(6) days, which agrees with the previously evaluated value. For 125Xe, we measured a half-life of 16.56(8) hours, slightly lower than the evaluated value.