The formation energies of small HenVm clusters (where n and m denoted the numbers of He atoms and vacancies, respectively) in Pu were calculated using molecular dynamics simulations and an embedded atom method potential, the Mores potential and the Lennard–Jones potential for describing the interactions of Pu–Pu, Pu–He and He–He, respectively. The binding energies of an interstitial He atom, an isolated vacancy and a self-interstitial Pu atom to a HenVm cluster were also obtained from the calculated formation energies of the clusters. All of the binding energies depended mainly upon the He–vacancy ratio (n/m) of clusters rather than the cluster size. With increase in the n/m ratio, the binding energies of a He atom and a Pu atom to a HenVm cluster decreased with the ratio, and the binding energy of a vacancy to a HenVm cluster increased. Helium atoms acted as a catalyst for the formation of HenVm clusters.

Molecular Dynamics Simulation of Helium–Vacancy Interaction in Plutonium. B.Ao, X.Wang, W.Hu, J.Yang: Journal of Nuclear Materials, 2009, 385[1], 75-8