The Role of Grain Boundaries in Self-Atom Collision Cascade

Recent research has shown the great potential of fusion power. The Plasma Facing Materials (PFM) is one of the crucial parts of the fusion reactor. Since the simulation study on the materials under extreme conditions has been more and more widely accepted, setting up an acceptable standard for conducting and characterizing these simulations became necessary and helpful. Our study provided a reasonable procedure for self-atom collision cascade simulations, and several methods to characterize the sample has been developed. With these methods, 2 types of grain boundary structures (Σ3<110>{112}, Σ5<100>{130}) with 3 different grain sizes (4nm, 6nm, 12nm) has been carefully studied. The preliminary results show that the behaviors differed with the distance between the cascade and grain boundary. Besides, the grain boundary configurations also affected the cascade behavior. The interaction between the cascade and grain boundary limited the sputtering and defect creating process. The damage on grain boundary varied with the grain boundary configuration. Based on those results, basic guidelines to design tungsten based PFM can be generalized.