Multifragmentation with GeV light-ion beams

Based on the experimental data obtained by a CR-39 plastic track detector we studied the characteristics of multifragmentation induced by GeV light-ion beams. In light-ion-induced reactions hot systems are formed with minimum initial compression and angular momentum and therefore it is supposed that they are the most suitable to study the thermal multifragmentation component. In such studies, of particular interest are the fragments with sub-Coulomb energies (E/A<3MeV). Since our detector has a very low detection threshold for examined fragments our analysis included the sub-Coulomb energy fragments from the largest energy interval to date. According to our results the sub-Coloumb energy fragments are the dominant part of the fragments emitted in interactions examined in our experiment. We applied the internal correlation study to reveal the mechanism of fragment production. The angular internal correlations suggested the simultaneous emission of fragments. In the analysis of the kinetic energy of fragments the 'hierarchy' effect is observed, i.e. the ranking in charge induces on average a ranking in a velocity of fragments. This requires involving the dynamical effects in the descriptions of the multifragmentation process. Our results indicate that the study of the internal correlations is a more accurate tool to test the pertinence of the models than the study of the correlations of the global observables which are even now mainly used in analysis