State-selective electron capture by slow C2+and C3+ions in atomic hydrogen

Abstract
Translational energy spectroscopy in a furnace target configuration has been used to identify the main collision channels in the process of one-electron capture by C2+ and C3+ ions in atomic hydrogen within the energy range 0.6-18 keV. For C2+ impact, collision channels involving both ground and metastable primary ions are unambiguously identified. In the case of C3+ impact, where only ground-state primary ions are present, the observed energy change spectra have been used to derive individual cross sections for capture into specific states of C2+. Most of the results are shown to be in reasonable agreement with the theoretical predictions of Beinstock et al. (1982) based on a full quantal analysis of the C3+-H(1s) system. The measurements provide the first detailed assessment of theory for such a process.