The evolution of radiation-induced point defects near symmetrical tilt Σ5 (310) <001> grain boundary in pure δ-plutonium: A molecular dynamics study

Abstract

The effects of the symmetrical tilt Σ5 (310) ⟨001⟩ grain boundary (GB) on the evolution of radiation-induced point defects in pure δ-plutonium (Pu) were studied by Molecular dynamics (MD) simulations. The evolution of radiation-induced point defects was obtained when primary knock-on atom (PKA) was respectively set as −15 Å and 15 Å far from the GB and the number of residual defects was obtained as the distance from PKA to GB was changed. According to the results, compared with vacancies, interstitial atoms were more easily absorbed by GB. In addition, the formation energy of point defects was also calculated. The results showed that there was almost no difference for the formation energy of vacancies in the all matrix. However, the formation energy of interstitial atoms close to the GB was lower than that in the other bulk regions.

Keywords

• Radiation
• Grain boundary
• Point defects
• Pure δ-plutonium
• Molecular dynamics