中国散裂中子源二期靶站关键部件辐照损伤模拟计算  

Calculation of radiation damage of key components of China Spallation Neutron Source II target station

作　　者：曹嵩 殷雯[1,2,3] 周斌 胡志良[1] 沈飞[1] 易天成[1] 王松林 梁天骄[1,2,3] Cao Song;Yin Wen;Zhou Bin;Hu Zhi-Liang;Shen Fei;Yi Tian-Cheng;Wang Song-Lin;Liang Tian-Jiao(Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;School of Nuclear Science and Technology,University of Chinese Academy of Sciences,Beijing 100049,China;Guangdong-Hong Kong-Macao Joint Laboratory of Neutron Scattering Science and Technology,Dongguan 523800,China)

机构地区：[1]中国科学院高能物理研究所,北京100049 [2]中国科学院大学核科学与技术学院,北京100049 [3]粤港澳中子散射科学技术联合实验室,东莞523800

出　　处：《物理学报》2024年第9期46-57,共12页Acta Physica Sinica

基　　金：国家自然科学基金联合基金(批准号:U1932219);广东省引进创新创业团队项目(批准号:2017ZT07S225);中德科学基金研究交流中心资助的中德合作交流项目(批准号:M-0728)资助的课题

摘　　要：中国散裂中子源一期工程于2018年通过国家验收,当前束流功率已经达到140 kW.为进一步提高靶站慢化器输出中子强度,已经提出中国散裂中子源二期500 kW功率升级计划.靶站关键部件长期受到高通量、高能量的粒子辐照,会产生较强的辐照损伤,影响着这些部件的使用寿命.本文首先使用PHITS3.33程序计算了钨、SS316不锈钢、6061铝合金3种材料的质子和中子原子离位截面以及氢、氦的产生截面,并分析了NRT(Norgett-Robinson-Torrens)模型和热平衡前原子复位修正(athermal recombination corrected,ARC)模型对材料离位损伤的影响.在此基础上结合中国散裂中子源二期靶站基线模型计算了靶站关键部件在500 kW的束流功率下运行5000 h产生的原子离位次数(displacement per atom,DPA)以及氢、氦的产额.计算结果表明,钨靶受辐照后产生的NRT-dpa,ARC-dpa,H和He产额最大值分别为8.01 dpa/y(1 y=2500 MW·h),2.39 dpa/y,5110 appm/y(atom parts per million,appm,每百万原子中产生该原子的个数)和884 appm/y.同样也计算了靶容器、慢化器反射体容器和质子束窗的辐照损伤值,根据这些部件的辐照损伤值预估了各自的使用寿命.这些结果对分析中国散裂中子源二期靶站关键部件的辐照损伤情况,构建合理的维护方案有着十分重要的意义.China Spallation Neutron Source(CSNS)I project passed the national acceptance in 2018,and current beam power has reached 140 kW.In order to further improve the output neutron strength of the target station moderator,a 500 kW power upgrade plan has been proposed for CSNS II.The target station is an important part of the spallation neutron source.In the target station,a large number of neutrons are produced by the spallation reaction between high energy protons and the target,these neutrons are moderated by the moderator and become neutrons for neutron scattering experiments.During operation,the target and other key components such as the target container,the moderator reflector container,and the proton beam window are irradiated by high-flux and high-energy particles for a long time,which will result in serious radiation damage.It is important to assess the accumulated radiation damage during operation to determine the service life of each component.At present,the physical quantities used to evaluate the radiation damage degree of materials include displacement per atom(DPA),H and He production.In this work,the displacement damage cross sections of protons and neutrons and the H,He production cross sections for W,SS316 and Al-6061 materials are obtained by using PHITS.The effects of the Norgett-Robinson-Torrens(NRT)model and athermal recombination corrected(ARC)model on the calculation of displacement damage are analyzed.The results show that the cross section calculated based on ARC model is lower than that based on NRT model,because the NRT model does not take into account the resetting of the atoms before reaching thermodynamic equilibrium.On this basis,DPA,H and He production of the key components of the target station operating for 5000 h at a power of 500 kW are calculated by combining the baseline model of the second phase target station of the spallation neutron source in China.The results show that the yields of NRT-dpa,ARC-dpa,H and He produced by irradiation are 8.01 dpa/y(in this paper,1 y=2500 MW·h),

关 键 词：中国散裂中子源二期靶站 辐照损伤 ARC-dpa PHITS模拟 

分 类 号：O571.53[理学—粒子物理与原子核物理]