A description of bubble growth and gas release of helium implanted tungsten

Bubble growth and gas release during annealing of helium implanted tungsten is described using a Kinetic Monte Carlo approach. Implantation of tungsten with low energy He ions results in the unusual formation of large numbers of oversized surface pores, which eventually lead to drastic changes of the tungsten surface morphology. Traditional rate-theory models are not suitable to simulate surface pore formation. Results of the KMC simulations illustrate the rapid formation of very large helium bubbles and surface pores. The simulation results agree well with observed results of low energy He implanted tungsten experiments, and thus provide an explanation for the observed surface morphology changes caused by low energy He implantation of tungsten.