Depth distribution of damage in copper irradiated with MeV, Ni and He ions

Transmission electron microscopy has been used to study radiation damage as a function of depth caused by 58 HeV and k MeV Ni 58 and 1 HeV He ions in copper single crystals at ambient temperature.The experimental damage density vs. penetration depth distributions have been compared with calculations which are based on the atomic collision theory of Lindhard et al. (LSS).For 58 MeV Ni 58 ions, the calculated damage profile using the theoretical LSS value of the electronic stopping parameter (k = 0.167) agrees well with experiment.However, for k MeV Ni 58 ions it is necessary to use k a 0.12 to get agreement with the experimental data.In the case of 1 HeV He, the depth location of the calculated damage peak is in good agreement with experiment when the electronic stopping determined by Chu and Powers is used whereas it is about 15% too close to the surface using the tables of Northciiffe and Schilling.