2013 Articles

Dissociative Recombination Measurements of HCl+ Using an Ion Storage Ring

Novotny, Oldrich; Becker, A.; Buhr, H.; Domesle, C.; Geppert, W.; Grieser, M.; Krantz, C.; Kreckel, H.; Repnow, R.; Schwalm, D.; Spruck, K.; Stutzel, J.; Yang, B.; Wolf, A.; Savin, Daniel Wolf

We have measured dissociative recombination (DR) of HCl+ with electrons using a merged beams configuration at the TSR heavy-ion storage ring located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. We present the measured absolute merged beams recombination rate coefficient for collision energies from 0 to 4.5 eV. We have also developed a new method for deriving the cross section from the measurements. Our approach does not suffer from approximations made by previously used methods. The cross section was transformed to a plasma rate coefficient for the electron temperature range from T = 10 to 5000 K. We show that the previously used HCl+ DR data underestimate the plasma rate coefficient by a factor of 1.5 at T = 10 K and overestimate it by a factor of three at T = 300 K. We also find that the new data may partly explain existing discrepancies between observed abundances of chlorine-bearing molecules and their astrochemical models.