A Comparison Between Calculated and Measured Neutron Sensitivities of a Pt Self-Powered Detector

There have been a number of experimental attemptsl,2 to determine the gamma and neutron responses of Pt self-powered (s-p) detectors in a reactor. The results of these measurements are subject to large uncertainties because a separation of the two components requires measurements in fields of differing neutron to gamma ratios. The problems arise from the difficulty of interrelating the results obtained under these different conditions. In this paper, we present a calculated result for the thermal neutron sensitivity of a Pt s-p detector using a model and computer program described elsewhere3. The accuracy of the computational method has been verified by a comparison between the calculated and measured neutron sensitivities of other s-p detectors. The calculated Pt result of 6.2 ± 10-24 A n-1 cm sec-1 turns out to be a factor of 1.5 lower than one of the experimental results and about 8 times lower than the other. Although the calculated and lower experimental results are quite similar, it is still felt that the former is the more accurate, based on 1) the difficulty and thus possible inaccuracy of the experiments, 2) burnup data, and 3) the established accuracy of calculations for other s-p detectors of similar type.