钨晶界与位错沉积强度偏差因子的动力学蒙特卡洛计算

沉积强度偏差因子定义为晶界或位错等沉积缺陷对间隙原子与空位的吸收能力的差异，可定量表征中子辐照条件下材料的辐照肿胀。核材料中本征缺陷及其辐照后的点缺陷等因素是影响材料本身性能的关键，精确计算沉积强度偏差因子十分必要且重要。.本项目针对未来抗辐照核材料设计的战略需求，以聚变面对等离子体钨基壁材料为载体，拟应用和发展自演化原子动力学蒙特卡洛方法，并结合分子动力学等模拟，系统计算不同类型的晶界和位错中点缺陷扩散动力学行为及其与晶界和位错的关系，发挥算法在考征原子尺度缺陷动力学过程和时空尺度模拟的优势，籍此高效准确获得钨中晶界和位错的沉积强度偏差因子，进而预测中子辐照核材料的肿胀率及其它力学性能，为未来抗辐照核材料设计提供有力依据和理论指导。

Bias factor of sink strength is defined as the absorption ability difference of SIA atom and vacancy by deposition defects such as grain boundary or dislocation. It’s a quantitative characterization of irradiation swelling of materials under neutron irradiation. The intrinsic defects and the point defects produced after irradiation in nuclear materials are the key factors affecting the properties of materials. Therefore, calculating the bias factor of sink strength accurately is essential and important..This project focuses on the major strategic needs of the future design of radiation resistant nuclear materials and takes W-based material, which is the most promising plasma wall facing material as carrier. We plan to use and develop the self-evolving atomistic kinetic Monte Carlo (SEAKMC) method, combined with molecular dynamics and other simulation methods to calculate the diffusion dynamics behavior of point defects, and its relationship with grain boundary/dislocation in grain boundary/dislocation of different parameters systematically. By using the advantages of algorithm in the investigation of the dynamic process of defects at atomic scale and the simulation at spatiotemporal scale, the bias factor of sink strength of grain boundaries and dislocations in tungsten can be obtained efficiently and accurately. Then the swelling rate and other mechanical properties of neutron irradiated materials can be predicted. We are aimed to provide a strong basis and theoretical guidance for the design of radiation resistant nuclear materials in the future.