Atomistic study of small helium bubbles in plutonium

An EAM (embedded atom method) potential is constructed for fcc δ-Pu. MD (molecular dynamics) simulations with the potential are performed to investigate the behavior of small He bubbles in Pu. The simulation results show that He bubble growth can be governed by the mechanism of dislocation-loop punching. The equilibrium structures of the He bubbles with different size are determined. It is clearly shown that dislocation loops are formed around the He bubbles. Moreover, the swelling of computational cells containing He bubbles is predicted.