Experimental Investigations of Ion—Molecule Reactions of D2+ with D2 and H2

Abstract

The reactions D₂⁺+D₂→D₃⁺+D and D₂⁺+H₂→(D₂H⁺, H₂D⁺)+(H, D) have been studied using an angular ion‐scattering apparatus in which the kinetic‐energy distributions of the various product ions have been measured for collision energies in the range 2–15 eV. The angular distributions of the D₃⁺ and D₂H⁺ product ions have also been determined, at primary beam energies in the interval 7–11 eV. The observed product‐ion kinetic‐energy distributions show that several endothermic reaction channels exist for these reactions. The most probable channels for D₃⁺ and D₂H⁺ formation are those in which the product ions are formed by a pickup process, in which very little momentum is transferred to the H or D atom. By comparing the results of these isotopic reactions, it is inferred that D₃⁺ is formed not only by D atom transfer to D₂⁺, but also by D⁺ ion transfer to the target D₂ molecule. Furthermore, at low collision energies, reaction channels corresponding to completely inelastic reactions in which all the center‐of‐mass collision energy appears as excitation energy of the product ions were observed for all three product ions.