MEASUREMENT OF BRANCHING RATIOS FOR THE DISSOCIATIVE RECOMBINATION OFCOLD HD+ USING FRAGMENT IMAGING

Two-dimensional fragment imaging is used to determine branching ratios into final atomic states for dissociative recombination of vibrationa lly cold HD+ molecules with electrons at variable energy. For low elec tron energies it is found that the dissociation proceeds via the (1) S igma(g)(+) state, leaving one of the fragments in the n = 2 level. At higher energies up to approximate to 20 eV, a pronounced angular aniso tropy of the fragmentation is found on one of the previously measured resonances, allowing for conclusions about the symmetry of the dissoci ating states.