The Role of Temperature on Irradiation Defect Evolution near Surfaces and Grain Boundaries in Tungsten

Abstract

This study explores the impact of temperature on defect dynamics in tungsten, emphasizing its application in nuclear fusion reactors as Plasma Facing Components (PFCs). Through atomistic simulations, the research elucidates the intricate interplay of defect production, annihilation, and redistribution under irradiation at room (300K) and elevated temperatures (1000K). It demonstrates that higher temperatures significantly increase the number and mobility of defects, leading to a substantial rise in the total number of surviving Frenkel Pairs (FPs), with a notable preference for surface distribution. This redistribution is attributed to energy gradient-driven relocation processes, enhanced by the defects' increased mobility at elevated temperatures. Moreover, the study reveals that elevated temperatures promote biased accumulation of interstitial defects in grain boundaries, especially in configurations that facilitate efficient interstitial migration, indicating a strategy for minimizing lattice interstitial accumulation under irradiation. These findings underscore the critical role of temperature in modulating irradiation-induced defect dynamics in tungsten, providing valuable insights for designing and selecting materials with optimized irradiation resistance for use in extreme conditions of nuclear fusion reactors. The research suggests a material design approach that accounts for temperature effects to enhance the durability and performance of nuclear fusion materials.