Molecular Dynamics Simulation of Diffusion Behavior of Self-Interstitial Atoms Cluster in Tungsten

Tungsten is considered as the most potential plasma-facing material in the future fusion reactor. However, in the real environment of future fusion reactor, 14 MeV high-energy neutron irradiation produced by deuterium-tritium fusion reaction will cause serious atoms displacement and various defects accumulation in materials. Here, self-interstitial atom and its clusters are the most common defects in neutron irradiation damage situation, so it is of great significance to study the aggregation and diffusion behavior of interstitial clusters. Molecular dynamics simulation is used to study the stable structures and formation energies of 1/2<111> and <100> self-interstitial atom clusters in tungsten, the diffusion behavior of 1/2<111> self-interstitial atom clusters with different sizes was also studied. The results will provide accurate and complete input parameters for larger-scale simulations such as Kinetic Monte Carlo and cluster dynamics, and provide the basis for correctly understanding and evaluating the neutron irradiation behavior in tungsten.