Microstructure evolution of cascade annealing in irradiated pure α-Zr: a molecular dynamics study

The microstructure evolutions of cascade annealing in α-Zr crystals at T=300K, 400 K, and 500 K for energy of 2, 6 and 10 keV with initially driving directions ⟨0001⟩ and ⟨011¯0⟩ of the primary knocked atoms are investigated by using molecular dynamics simulations. The results show that the relaxation time (τr) of cascades can play the role of an effective parameter for describing radiation damages during molecular dynamics simulations. τr of cascade with the larger surface area but with the same volume is much smaller, which promotes faster recombination of defects during cascade annealing. Energy is a crucial factor in the formation of cascade displacements of atoms and appearing of defects compared with temperature and direction of movement for initially knocking atoms.