Molecular dynamics simulation of the formation, growth and bursting of bubbles in tungsten exposed to high fluxes of low energy deuterium

Abstract

Molecular dynamics simulations are carried out to investigate the formation, growth and bursting of bubbles in tungsten exposed to the irradiation of an extremely high deuterium flux. It is found that the bubbles form in the region near the location of the implanted ion distribution peaks, and that the effect of the substrate temperature on the bubble formation depth is negligible; it is also found that the percentage of deuterium that is found in D2 molecules increases as the bubble grows, and that the evolution of the bubble’s internal pressure is strongly associated with the properties of its surrounding structure. The simulations display the development of a dome-shaped structure at the tungsten surface during the bubble growth. The merging of two deuterium bubbles is also observed. The present simulations also show that the bubble bursts by generating a partially opened lid, which has already been observed in previous independent experiments.