Dynamics of the multifragmentation of 1A GeV gold on carbon

An exclusive study of the interaction of 1A GeV Au with C shows a separability into two stages: a prompt stage involving emission of most Z = 1 and some Z = 2 particles and a second stage involving the decay of an equilibrated remnant, which typically undergoes multifragmentation. The mean mass, charge, excitation energy, and the initial temperature T-i of the remnant have been determined as a function of the total charge multiplicity, m, as has the freeze-out temperature T-f. Both T-i and T-f increase linearly with m and their values at the critical point have been determined. T-f rises monotonically with excitation energy as expected for a continuous phase transition.