Tungsten has been chosen as the divertor armour material in ITER and is the main candidate material for plasma-facing components for future fusion reactors. Interaction of plasma components with the material leads to degradation of the performance and thus the lifetime of the in-vessel components. On top of that special attention is drawn to tritium retention in the reactors vessel from a safety point of view, since tritium is radioactive material. In order to gain better understanding of the mechanisms driving accumulation of plasma components in the material and subsequent degradation of the material, atomistic simulations are employed. The focus of this work is on so-called self trapping of H and He atoms or, in other words, Frenkel pair formation in bulk tungsten in the presence of H and He atoms. Two versions of a model embedded atom interatomic potential and a bond order potential were tested by comparing it with ab initio data regarding the binding properties of pure He and He-H-Vacancy clusters and energetics of Frenkel pair formation. As a result of Molecular Dynamics simulations at finite temperature, the values of critical H concentration needed for the generation of a Frenkel pair in the presence of He clusters were obtained. The results show that the critical H concentration decreases with the size of He cluster present in the simulation cell and thus, Frenkel pair formation by H is facilitated in the presence of He clusters in the material.

钨已被选为国际热核实验堆的分流器装甲材料，并且是未来聚变反应堆面向等离子体部件的主要候选材料。等离子体组分与材料的相互作用导致性能下降，并因此导致血管内组分的寿命降低。最重要的是，从安全的角度特别注意tri在反应堆容器中的保留，因为tri是放射性物质。为了更好地理解驱动等离子体成分在材料中累积以及随后材料降解的机理，采用了原子模拟。这项工作的重点是所谓的H和He原子的自陷，或者换句话说，在H和He原子存在的情况下，在体钨中形成Frenkel对。从头开始的数据，有关纯He和He-H-空位簇的结合特性以及Frenkel对形成的能量。在有限温度下进行分子动力学模拟的结果是，获得了存在He团簇时生成Frenkel对所需的临界H浓度值。结果表明，临界H浓度随模拟单元中He簇的大小而降低，因此，在材料中存在He簇的情况下，H促进了Frenkel对的形成。