Helium induced void and bubble formation in MgO

Trapping of helium in magnesium oxide vacancies and vacancy clusters is studied using empirical potential calculations. Based on the results, a rate-theory model is formulated in order to simulate the kinetics and long time dynamics of helium trapping. The simulations are in good agreement with helium annealing experiments in the literature. In particular, the tendency for helium to stabilise vacancy clusters is found to be strongly dependent on He concentration and temperature.