Assessing the influence of electronic effects on molecular dynamics simulations of primary radiation damage in tungsten

Molecular dynamics (MD) simulation is extensively used in the research on the evolution of cascade damage. Considering their capability of transferring energy from atoms to electrons, the electronic effects, including electronic stopping (s(e)) and electron-phonon coupling (EPC), cannot be negligible in the MD simulations. However, how to incorporate them is somewhat debatable, and their influence on simulation results is still not very clear. In the present study, the sensitivity research of collision cascades in tungsten caused by individual primary knock-on atoms to the parameters of se and EPC is approached methodologically. The results show that se influences the defects produced in the thermal spike and the size distribution of residual defect clusters more significantly, whereas EPC affects the number and space distribution of residual defects more remarkably. In addition, the simulation results depend appreciably on the choice of cutoff energies of s(e) and EPC.