Electron emission and fragmentation of C60 in collisions with energetic particles

We have studied ionization and fragmentation of C-60 induced in collisions with fast helium, silicon and gold ions. Fragment ions and electrons produced were measured simultaneously in coincidence with outgoing charge-selected projectile ions. By means of this triple coincidence method we obtained successfully detailed information about the correlated emission process between electrons and fragment ions. It was found that the number of emitted electrons n(e) depends strongly on. the cluster size of fragment ions and ne increases with decreasing cluster size. Also, we found that, with increasing atomic number of the projectile ions, the C-60-multi-fragmentation becomes more prominent and the value of n(e) increases as well, indicating clearly the importance of electronic excitation effects. As a more important new result, it was found that the multi-fragmentation is induced rather strongly even in such collisions where only a few electrons are emitted. It is safely concluded that the accompanying internal excitation plays an essential role in the C-60-multi-fragmentation. (C) 2004 Elsevier Ltd. All rights reserved.