Astrochemistry in an Ion Storage Ring

Storage ring studies of low energy electron collisions with molecular ions have been carried out for dissociative recombination (DR) of fluorine-bearing molecules. Here we report on work aiming to improve the understanding of astrochemistry involving HF, a possible spectroscopic tracer of interstellar H2. For CF + the rate coefficient was obtained for temperatures down to 10 K. For D2F + the DR fragmentation branching ratios were determined to be 66(3)%, 24(2)%, and 10(2)% for the F+D+D, DF+D, and D2+F channels, respectively. The molecular DR products of this reaction, DF and D2, display an unusually high level of internal excitation, close to their dissociation limit.