Energy and angular distributions of secondary ions from a C 60 surface induced by fast heavy ion impacts

Abstract

We have measured energy and angular distributions of secondary ions emitted from a C 60 film target bombarded by 4-MeV 28Si 3+ ions by using a time-of-flight coincidence method. Fullerene-like secondary ions of C 60−2 n + and C 60+2 n + ( n=1–5) as well C 60 + ions and multiples of C 60 such as C 60 N + ( N=2, 3) ions were observed strongly. It is found that the angular distributions of C 60 + ion are roughly symmetric with respect to the surface normal of the target. On the other hand, the angular distribution of C 62 ions is found to be slightly inclined from the surface normal. The present result indicates that fullerene-like ions may be produced predominantly via the mechanism predicted by the pressure-pulse model developed for fast heavy ions.