A crossed beam study of the charge-transfer reaction of Ar+ with N2 at low and intermediate energies

The charge-transfer reaction Ar+(N2,Ar) N+2 was studied in a crossed beam experiment at 1.73 and 4.01 eV collision energies. A weak plasma ion source was used to generate a nearly pure Ar+ (2P3/2) ion beam, which is crossed at 90° by a He-seeded supersonic jet N2 beam. Detailed analysis of the results demonstrates that the reaction proceeds cleanly to generate N+2(X Σ+g, v=1) with a distribution of rotational states. A direct mechanism, qualitatively described as electron jump with negligible momentum transfer, is followed at collision energies of 1.7 and 4 eV.