In our study we investigated CR-39 samples irradiated by O-16 and Kr-8
4 ions with energy 126 MeV and 209 MeV, respectively. We observed almo
st all of the possible processes on the surface. We found track cores
(10-20 nm) surrounded by a much larger molehill-like halo with a diame
ter of 100-500 nm, corresponding to the electron collision cascade. We
observed tubes roughly 1000 nm long with a diameter of 50-100 nm.