A molecular dynamics-based comparison of defect production in collision cascades during the bombardment of iron with different ions

We present a computer simulation study on the influence of incident ions on the energy transferred to primary knock-on atoms (PKAs) and defects produced in the cascade collision of irons. Three types of ions (H, Fe, and Xe, which are frequently used in irradiation experiments) with an energy of 3 MeV were simulated. According to the calculation results of SRIM, the average energy transferred to PKAs by Fe ions was the highest among the three types. Then, cascade collisions induced by PKAs with different energies were simulated by the molecular dynamics method. The maximum number of defects produced during irradiation increased, and the time taken by defect number peak formation was extended with the increased energy of PKAs. The difference in radial distribution function between pre- and post-irradiation irons showed that a higher energy of PKA transferred resulted in a flatter curve. Besides, the law of defects varying in temperature was also investigated. All the researches imply that heavy ions can substitute for neutrons in irradiation experiments which is a practicable way, but the influence of conditions must be taken into account.