中子诱发^(232)Th裂变初始碎片质量及动能分布Monte-Carlo研究  

Monte-Carlo study of pre-neutron emission mass and energy for neutron-induced ^(232)Th fission

作　　者：刘昌奇 霍东英 韩超 吴康 刘兴宇 杨旭 白晓厚 王俊润 张宇[1,2] 姚泽恩[1,2] 韦峥[1,2] Liu Chang-Qi;Huo Dong-Ying;Han Chao;Wu Kang;Liu Xing-Yu;Yang Xu;Bai Xiao-Hou;Wang Jun-Run;Zhang Yu;Yao Ze-En;Wei Zheng(School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China;Engineering Research Center for Neutron Application,Ministry of Education,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学核科学与技术学院,兰州730000 [2]兰州大学中子应用技术教育部工程研究中心,兰州730000

出　　处：《物理学报》2022年第1期51-59,共9页Acta Physica Sinica

基　　金：国家自然科学基金委员会-中国工程物理研究院联合基金(批准号:U1830102);国家自然科学基金(批准号:12075105,11875155,11705071);国家自然科学基金委员会-中国核工业集团有限公司核技术创新联合基金(批准号:U1867213);中央高校基本科研业务费专项资金(批准号:lzujbky-2021-kb09);甘肃省引导科技创新发展专项资金(批准号:2018ZX-07)资助的课题。

摘　　要：随着第四代反应堆以及先进核能利用系统的发展,对中子核数据提出了高精度、多核素、宽能区的新要求.目前,中国核数据评价库(CENDL库)中相关核裂变的数据较缺失,不足以满足当前核能发展的需求.因此,建立面向中子核数据需求的可靠计算方法和工具变得极为重要.本文基于Monte-Carlo方法建立了裂变碎片质量动能计算模型,研究了中低能中子诱发232Th(n,f)反应发射中子前裂变碎片的分布特性.对于裂变碎片质量分布,本模型计算结果与实验值最大偏差约1%,与GEF,TALYS程序计算结果(与实验值最大偏差约2%)相比具有一定优势.对于发射中子前裂变碎片动能分布,本模型计算结果与实验数据一致.结果表明,所发展的计算模型能够较好地预测^(232)Th(n,f)反应发射中子前裂变碎片数据,为中子诱发锕系核裂变反应计算提供一种新思路.The development of fourth-generation reactors and advanced nuclear energy systems require high-precision,multi-nuclide,and wide-energy-area neutron nuclear data.However,the current nuclear energy-related nuclear fission data in the China Nuclear Data Evaluation Library(CENDL library)are incomplete and cannot meet the current need.It is extremely important to establish the reliable calculation methods and tools for the neutron nuclear data.Based on the Monte-Carlo method,a model for calculating the pre-neutron fission fragment is established in this work.The mass and kinetic energy distribution of 232Th(n,f)reaction at the medium-and low-incident neutron energy are studied.The calculations of the mass distribution with the different values of incident energy are compared with the experimental results.The maximum deviation of this work from the experimental data is~1%,which is advantageous compared with the GEF and TALYS code(maximum deviation from the experimental value is~2%).The calculation of the pre-neutron fission fragment kinetic energy also shows good agreement with experimental result.The results indicate that this model can well describe and predict the characteristics of pre-neutron fission fragment for ^(232)Th(n,f)reaction at the medium-and low-incident neutron energy.It also provides a new idea for calculating the neutron-induced actinide fission reactions.

关 键 词：发射中子前裂变碎片 质量分布 总动能分布 蒙特卡罗方法 

分 类 号：O571.5[理学—粒子物理与原子核物理]