Mechanism of secondary ion emission from an Al sample under MeV heavy ion bombardment

Sputtering yields and kinetic energy distributions (KED) of Al atomic ions ejected from a pure aluminum sample under MeV silicon ion bombardment were simulated with the molecular dynamics (MID) method. Since the electronic energy loss (S-e) is much higher than the nuclear energy loss (S-a) when the incident ion energy is as high as several MeV an S-e effect was also taken into consideration in the simulation. It was found that the simulated sputtering yield fits well with the experimental data and the electronic energy loss has a slight effect at incident ion energies higher than 4 MeV. The simulated secondary ion KED spectrum is a little lower in the peak energy and narrower in the peak width than the experimental.