Alkali-negative-ion–molecule collisions

Absolute total cross sections for electron detachment and charge transfer (including dissociative charge transfer) have been measured for collisions of Na^- and K^- with H₂, D₂, N₂, O₂, CO, CO₂, and CH₄ targets. The collision energies of this investigation range from the energetic thresholds for detachment up to 300 eV (in the laboratory frame). In this energy range, electron detachment is observed to be the dominant process for all of the targets except O₂. For several of these systems, a simple optical model can be used to reproduce the observed values of the cross sections for detachment. In the case of the CO₂ target, some of the detached electrons appear to be due to charge transfer to metastable CO₂{}^{{{-}}}$. Significant isotope effects are observed for the ${H}₂$ and ${D}₂$ targets.