Multifragmentation of a very heavy nuclear system (II): bulk properties and spinodal decomposition

The properties of fragments and light charged particles emitted in multifra gmentation of single sources formed in central 36 A MeV Gd + U collisions a re reviewed. Most of the products are isotropically distributed in the reac tion c.m. Fragment kinetic energies reveal the onset of radial collective e nergy. A bulk effect is experimentally evidenced from the similarity of the charge distribution with that from the lighter 32 A MeV Xe + Sn system. Sp inodal decomposition of finite nuclear matter exhibits the same property in simulated central collisions for the two systems, and appears therefore as a possible mechanism at the origin of multifragmentation in this incident energy domain. (C) 2001 Elsevier Science B.V. All rights reserved.