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采用分子动力学方法模拟了氦在金属钨中的扩散聚集行为.首先,建立了氦与钨原子间相互作用势,短程部分采用ZBL势形式,长程部分采用从头算法数据,实现了两者之间的平滑连接.通过计算氦在钨中不同间隙位的形成能发现,单个氦原子更易存在于金属钨中的四面体间隙位,这与最新的研究成果是一致的.在400—1200K的温度范围内,考察了氦原子在金属钨中的扩散行为,获得了扩散迁移能,其值介于实验值和从头算法结果之间.最后,研究了氦的聚集行为,从能量的角度考察了氦团簇形成初期的生长机理.研究发现,在氦团簇形成初期,氦团簇对氦的结合能随着氦团簇的生长有逐渐增大的趋势,说明氦团簇吸收氦的能力逐渐增强.
The molecular dynamics simulation is used to simulate the diffusion and aggregation behavior of helium in tungsten.Firstly, the interaction potential between helium and tungsten atoms is established, the ZBL potential is used as the short-range and the ab initio data is used as the long- By calculating the formation of helium in different gaps in tungsten can be found in a single helium atoms more likely to exist in the metal tungsten in the tetrahedral interstitial position, which is consistent with the latest research results in the temperature range of 400-1200K , The diffusion behavior of helium atom in tungsten was investigated and the diffusion transfer energy was obtained, which is between the experimental value and the ab initio method.Finally, the aggregation behavior of helium was studied, and the helium cluster In the initial stage of the formation of helium clusters, the binding energies of helium clusters to helium clusters gradually increase with the growth of helium clusters, indicating that the ability of helium clusters to absorb helium gradually increases.