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 ha ve been measured for high energy H-25(+) cluster ions (60 keV amu(-1)) colliding with a neutral C-60 target. In contrast to earlier collisio n experiments with a helium target the present studies do not show a U -shaped fragment mass distribution, but a single power-law falloff wit h increasing fragment mass. This behaviour is similar to what is known for the intermediate regime in nuclear collision physics and thus con firms a recently predicted scaling from nuclear to molecular collision s. (C) 1997 Elsevier Science B.V.