材料中He深度分布演化的Monte Carlo模拟研究

基于He泡生长的迁移-合并机理,用Monte Carlo方法模拟了对材料进行等温退火过程中He深度分布的演化,探讨了不同参数对这一演化的影响.研究表明:材料中He泡的初始浓度和尺寸将影响He深度分布的变化,而退火温度则对演化速率起重要作用但对最终的He深度分布影响较小;随着反应的进行,整个系统的演化是逐渐趋缓的. 关键词： He 深度分布 Monte Carlo模拟     

Justification of a Monte Carlo Algorithm for the Diffusion-Growth Simulation of Helium Clusters in Materials

A theoretical analysis of a Monte Carlo （MC） method for the simulation of the diffusion-growth of helium clusters in materials is presented. This analysis is based on an assumption that the diffusion-growth process consists of first stage, during which the clusters diffuse freely, and second stage in which the coalescence occurs with certain probability. Since the accuracy of MC simulation results is sensitive to the coalescence probability, the MC calculations in the second stage is studied in detail. Firstly, the coalescence probability is analytically formulated for the one-dimensional diffusion-growth ease. Thereafter, the one-dimensional results are employed to justify the MC simulation. The choice of time step and the random number generator used in the MC simulation are discussed.