Multifragment Decay of Highly Excited Nuclei

Coincidences between at least three fragments emitted at large angle have been used to study central collisions in the Ar+Au reactions at 30 and 60 MeV/u incident energies. For both energies, the formation of equilibrated very hot nuclei is evidenced. Average excitation energy as high as 1.2 GeV is reached in the reaction at 60 MeV/u. The increase of the excitation energy deposited for the upper bombarding energy is confirmed by the correlated increases of the nuclear temperature and of the evaporated light-particle multiplicity