Molecular dynamics simulation of structural changes in metals under irradiation with high-energy heavy ions

Abstract

To study the processes of irradiating metals with high-energy heavy ions, a thermal spike model is often used, i.e., a system of electron-gas thermal conductivity equations and a lattice. Upon the irradiation of materials with high-energy heavy ions, more than 90% of the energy is consumed in the excitation of the electronic subsystem of the irradiated material. Further, this energy is transferred to the lattice subsystem and there is high heating of the lattice in a small volume, which can cause melting (evaporation), resulting in a structural change (amorphization, formation of high pressure areas, tracks, etc.) in the irradiated material. This work is devoted to studying structural changes in the surface of nickel by irradiation with high-energy ions of uranium. The thermal spike model is used for the initial distribution of temperature conditions in the irradiated nickel, which imitates the action of radiation on a molecular-dynamic system. The further evolution of the system is studied by molecular dynamics. As part of this approach, the processes of structural changes on the surface of the irradiated target can be investigated in more detail.