Explosive multifragmentation in theS32+27Al reaction at 37.5 MeV/nucleon

We describe an experimental study of the [sup 32]S+[sup 27]Al reaction at 37.5 MeV/nucleon carried out with the AMPHORA multidetector. A small fraction of events in which the total charge was detected and which are shown to originate mainly from central collisions have been isolated and compared with statistical decay model predictions. Dynamical properties provide strong evidence for a radial directed collective component (blast wave) in the fragment energies which dominates the interfragment Coulomb repulsion and the thermal motion.