Determination of the half-life of 233Pa

The half-life of 233Pa has been determined by following the emission rates of eight gamma rays from the decay of 233Pa produced by neutron irradiation of 232Th. Several data evaluation procedures were used in the analysis of the half-life data. The measured half-life resulting from these measurements is 27.02(3) days. An evaluation in conjunction with 4 literature values leads to 26.975(13) days as the current best estimate of the half-life of 233Pa.