DISSOCIATION OF H-2 AND CO BY SLOW MULTIPLY-CHARGED IONS

We have studied the time of flight spectra of molecular ions and charged fragments resulting from collisions of 2 keV/amu He2+ and 1 keV/amu O-q+ (q = 1-5) ions with CO and H-2 molecules respectively. We found that the energy release from dissociation of CO after He2+ impact is smaller than what one calculates assuming pure Coulomb explosion. For the O9+ + H-2 system we can identify two processes leading to H+ formation, one with an energy gain for the two protons of around 14 eV, the other yielding very slow fragments. The latter is probably due to one-electron transfer processes and cannot be explained assuming pure Frank-Condon type transitions.