Mass distribution and multiple fragmentation events in high energy cluster-cluster collisions: evidence for a predicted phase transition

Fragment size distributions including multiple fragmentation events have been measured for high energy H + 25 cluster ions (60 keV amu −1 ) colliding with a neutral C 60 target. In contrast to earlier collision experiments with a helium target the present studies do not show a U-shaped fragment mass distribution, but a single power-law falloff with increasing fragment mass. This behaviour is similar to what is known for the intermediate regime in nuclear collision physics and thus confirms a recently predicted scaling from nuclear to molecular collisions.