A molecular dynamics simulation study of displacement cascades in vanadium

Abstract

Molecular dynamics calculations were performed to simulate the primary state of radiation damage processes in vanadium. The interaction of atoms was described by the embedded atom method (EAM) potential that was modified at close atomic separation to merge smoothly with the universal ZBL-potential for description of the higher energy recoils in cascades. The initial development of displacement cascades was observed to consist of replacement collision sequences (RCSs) and subsequent molten structures at the centers of cascades. We evaluated the efficiencies of defect production in the displacement events initiated from recoils with kinetic energies of up to 20 keV. The Frenkel pair production is found to have a power-law dependence on the primary recoil energies. The energy dependence is obviously different between single and multiple Frenkel pair production. The efficiencies of defect production and cascade mixing are somewhat higher and lower in bcc vanadium cascades, respectively, than those of fcc metals.