DISSOCIATIVE RECOMBINATION OF HD+ IN SELECTED VIBRATIONAL QUANTUM STATES

Rate coefficients for dissociative recombination of HD+ in selected vi brational states have been measured by a combination of two molecular fragment imaging methods by using the heavy-ion storage ring technique . Recombination fragment imaging yields state-to-state reaction rates. These rates are converted to rate coefficients by using vibrational l evel populations of the stored ion beam, derived from nuclear coordina te distributions measured on extracted ions. The results show strongly increasing rate coefficients for high vibrational excitation, where a dditional dissociation routes open up, in agreement with a theoretical calculation. Very low rate coefficients are found for certain, isolat ed vibrational states.