0.57、1.0和1.5 MeV中子诱发<sup>235</sup>U裂变的<sup>99</sup>Mo产额绝对测量

0.57、1.0和1.5 MeV中子诱发²³⁵U裂变的⁹⁹Mo产额绝对测量

摘要: 用HPGe γ能谱法绝对测量了0.57、1.0和1.5 MeV中子诱发²³⁵U裂变产物⁹⁹Mo的产额，使用双裂变室测量了样品辐照过程中的裂变率，应用MCNP ⅣB模拟了铀样品中的中子能谱，并讨论了非主中子的各种来源对产额数据的影响。得到⁹⁹Mo在0.57、1.0和1.5 MeV的产额分别为6.61%、6.62%和6.28%。本工作与美国阿贡实验室的结果有15%以上的相对偏差，主要是由引用的衰变数据不同引起。对阿贡实验室数据进行校正后，本工作与阿贡实验室数据的相对偏差处于实验不确定度范围内。

Abstract: The chain yields of fission product ⁹⁹Mo were determined for the fission of ²³⁵U induced by 0.57, 1.0 and 1.5 MeV neutrons. Absolute fission rate was monitored with a double-fission chamber. Fission product activities were measured by HPGe γ-ray spectrometry. MCNP ⅣB was applied to simulate neutron spectrum in uranium samples, and the effects of all kinds of secondary neutrons on fission yield data were discussed. The fission yields of ⁹⁹Mo for 0.57, 1.0 and 1.5 MeV neutrons are 6.61%, 6.62% and 6.28%, respectively. The yield data were compared with those of ANL. Our results are in agreement with those of ANL within the scope of experimental uncertainties after necessary corrections.