NECK INSTABILITIES IN DEEP-INELASTIC COLLISIONS AT MEDIUM ENERGIES

A novel reaction mechanism for semi-peripheral heavy ion collisions is discussed, due to new features of the nuclear dynamics in the overlap ping region. In a very selected beam energy range, between 40 and 70 M eV/u, we see the onset of new neck instabilities coupled to an increas ing amount of dynamical fluctuations. Expected consequences are a poss ibility of intermediate mass fragment emission from the neck region an d large variances in the projectile-like and target-like observables.