Velocity and charge state dependences of molecular dissociation induced by slow multicharged ions

Dissociation of CO molecules by collisions with He2+ and O7+ at keV energies has been investigated by measuring the charge states and kinetic energies of the ionized fragments in coincidence with each other. As opposed to earlier investigations with fast (MeV) projectiles we find that the kinetic energies of the fragment ions are strongly influenced by the projectiles' charge and velocity; e.g., O7+ impact results in 50% less kinetic energy release in the C+-O+ fragmentation than He2+ impact. For a qualitative understanding of these effects we invoke the classical overbarrier model.