中低能中子诱发^(238)U裂变的碎片质量分布

Pre-neutron-emission Mass Distributions for Neutron-induced ^(238)U Fission at Low and Intermediate Energies

乏燃料中238U含量最多(高达95%),研究中子诱发238U裂变产物的分布特性对乏燃料的循环后处理具有非常重要的意义。本文基于微观和唯象方法的裂变势模型理论,研究入射能量从0.9MeV—60.0MeV能区的中子诱发238U裂变反应的发射中子前碎片质量分布,结果表明:在中能区,理论计算结果能很好地重现实验数据,甚至比国际著名的TALYS理论计算的结果要好;在低能区,理论计算结果也较为合理,并分析了与实验数据有所偏差的原因。

238U,of which abundance is almost 95%,is one of the most important isotopes of the spent nuclear fuel.The study of neutron-induced 238U fission is in favor of the cycle processing of the spent fuel.Based on the microscopic and phenomenological approach,the pre-neutron-emission mass distributions of neutron-induced 238U fission at incident energies from 0.9 to 60 MeV have been studied with the fission potential theory proposed in previous paper.The calculated results could well reproduce the experimental data,and are even better than that of the famous TALYS code at intermediate energies.The results can also reasonably predict the distributions at the vibrational resonances,and the deviation between the experimental and the theoretical data is also analyzed.