COLLECTIVE DYNAMICS OF NUCLEAR-FUSION - DEFORMATION CHANGES AND HEATING DURING THE FUSION

The formalism developed elsewhere for the theoretical description of t he dynamics involved in the heavy nuclei fusion is applied in this pap er to study the ''history'' of the fusion of two identical heavy nucle i experiencing central collision. The evolution of the shape and of th e temperature of symmetrical fusing systems is studied, The role of th e elastoplasticity of nuclear matter in the nonmonotonical changes of the shape is elucidated in this way. A tentative explanation of the '' extra push'' phenomenon is given in terms of the competition between e lastic properties of fusing systems driving to the re-separation of co lliding nuclei and the dissipative (plastic) properties of nuclear mat ter transforming the energy of collective motion into the energy of st atistical excitation and thus leading to the fusion. The fingerprints of the heavy-nuclei fusion history as it is depicted by the model ale traced in the anisotropy of the dipole and quadrupole gamma-radiation emitted during the fusion. The parallels in the description of the fus ion dynamics given by the simple model used in this paper and by the m ore fundamental approaches based on the kinetic equation are emphasise d.