聚变堆中子对第一壁辐照损伤的计算机模拟研究

COMPUTER SIMULATION OF RADIATION DAMAGE IN THE FIRST WALL CAUSED BY FUSION NEUTRON

用蒙特卡罗方法建立了适用于静态复成分非晶态靶的中子输运和带电粒子辐照损伤连接模拟程序．在模拟带电粒子级联碰撞时，特别考虑了替位碰撞，修正后的ＤＰＡ（ＤｉｓｐｌａｃｅｍｅｎｔＰｅｒＡｔｏｍ）值比未考虑时减少了１０％～２０％；同时统计了ＤＰＡ中反常替位所占的比例。用此程序模拟研究了聚变堆中子对两种第一壁候选材料的辐照损伤，计算了中子辐照在材料中引起的ＰＫＡ（ＰｒｉｍａｒｙＫｎｏｃｋ—ｏｎＡｔｏｍ）、气体产生率、ＤＰＡ以及它们的深度分布。计算结果表明，中子引起的辐照损伤基本上为均匀的体损伤；计算的ＰＥ—１６材料的ＤＰＡ值比ＳＳ３１６的稍高，氢气体产生率近似为ＳＳ３１６的两倍；氦气体产生率为ＳＳ３１６的１．４５倍；所用聚变堆第一壁中子对ＰＥ—１６材料的辐照损伤比对ＳＳ３１６的严重。计算中使用的核数据来自ＭＣ（８７）ｎ数据库。

A neutron transport code and a changed-ion radiation damage code have been linked to simulate neutron induced defects in the static. multi-component amorphous forget. In simulating collision cascades, replacement collisions have been taken into account, especially. It corrected the value of DPA about 10%～20%. Improper replacements were recorded also. The radiation damage in two kinds of materials candidated for the first wall in fusion reactor is calculated. Calculation gives the production rates of PKA and DPA, gas production rates and their depth distributions. The resultS show that damage distributions are almost uniform body distributions, the DPA value of PE-16 is a little larger than that of SS316, the hydrogen production rates is nearly two times as much as that of SS316, the helium production rates is 1.45 times as much as that of SS316. It means that the radiation damage of PE-16 is more serious than that of SS316. The cross section data from MC(87) n library is used in the calculation.