Heavy ion interaction at energies of approximately 10 MeV/nucleon and nonequilibrium processes in nuclei

Reviewed are experimental data on preequilibrium emission of light particles in heavy ion reactions at 10 MeV/nucleon energy. Discussed is a number of hypotheses: emission of nonevaporating alpha particles at the expense of central and peripheral collisions, formation of local heating region in a contact zone of colliding nuclei etc. Theoretical models suggested for describing preequilibrium emission were analyzed. Suggested is a model of preequilibrium emission based on the assumption of predominant excitation of collective oscillations of nuclear substance density at an initial stage of the reaction