Surface-mediated reduction of ion-irradiation-induced damage in tungsten revealed by advanced ion channeling analysis

Abstract

Tungsten is a leading candidate material for plasma-facing components in future fusion reactors. In this work, we integrate advanced ion channeling analysis with large-scale molecular dynamics simulations to uncover a pronounced surface-mediated reduction of radiation damage in single-crystal tungsten at elevated temperatures. We demonstrate how our unique analysis method can clearly resolve a dislocation-free zone near the surface and a transition region with suppressed defect density before reaching the bulk value. A possible explanation for the strong surface effect at elevated temperatures can be obtained by considering the coherent drift motion of dislocation loops toward the surface.