Loop-punching suppression induced by growth of helium bubble pair in tungsten

Molecular dynamics and transmission electron microscopy are employed to study the formation and evolution of interstitial dislocation loops due to nearby growing helium bubbles. The study reveals a novel mechanism that suppresses further formation of loops. Mass transport of self-interstitial atoms between the bubbles is observed, followed by the loop formation, resulting in a loop-bubble complex in which the Burgers vector may rotate between and 1/2 . Such a complex can absorb free loops, effectively influencing the evolution of loop number density. These results provide a new understanding of loop-bubble complex formation and saturation of the loop density under continuous helium implantation in materials.