中子入射砷核同位素反应全套微观数据的计算与分析

Theoretical calculations and analysis of the full set of microcosmic data for n+^(74,75,77,79)As nuclear reaction

基于光学模型假设和中子与天然砷反应的总截面、去弹截面以及弹性散射角分布的实验数据,获得了一组0.1~20 MeV能量区域内普适于中子与砷核同位素反应的光学势参数。并以该组光学模型参数为前提,利用以光学模型、扭曲波Born近似理论、统一的Hauser-Feshbach统计理论和激子模型等理论为核心的UNF程序,计算了中子与As及其同位素的反应截面、能谱和双微分截面值,并对理论计算值和实验数据进行了比较和分析,理论计算结果与实验数据符合较好,同时给出了无实验数据的区域的理论结果。

[Background] As one of the fourth generation of nuclear energy system, thorium molten salt reactor nuclear energy system（TMSR） has been greatly improved in sustainability, safety, economy and reliability. In the design and manufacture of TMSR, a large number of nuclear reaction data is indispensable. [Purpose] The full set of microcosmic data for n＋74,75,77,79As reaction, including the theoretical calculations of total cross section, elastic cross section, various of reaction channels cross section, elastic and inelastic scattering angular distribution, energy spectra and double differential cross sections for six kinds of emitted particles（n,p,α,d,t,He-3）, would be calculated. [Methods] Based on the assumption of the optical model and the experimental data of total cross section and elastic scattering angular distributions for n＋75As reaction, a set of optimal optical potential parameters which universally suitable for n＋74,75,77,79As are obtained. On the premise of the parameters, the cross sections, energy spectra and double differential cross sections for n＋74,75,77,79As reaction are calculated and analyzed by the UNF program which based on the optical model, distorted wave Bom approximation theory, the unified Hauser-Feshbach theory and exciton model. [Results] The theoretical results of the full set of microcosmic data are in agreement with the experimental data, and the theoretical results of regions without experimental data are given. [Conclusion] The full set of microcosmic data for n＋74,75,77,79As reaction based on this set of optical potential parameters is reasonable, the main theoretical model can describe the nuclear reaction commendably, the full set of microcosmic data obtained in this work can meet the requirements of nuclear engineering and medicine, it also has significance for the study of nuclear reaction.