Excitation energy transfer and charge exchange during collisions of N+(1S) and N+(5S) with N2

Measurements of charge exchange between N⁺ and N₂ are reported for low product-ion energies and nearly zero center-of-mass scattering angles. The principal scattering is attributed to N⁺( ¹S) with major contributions from the ⁵S state. Fine structure corresponding to the transfer of excitation energy between the incident ion and the vibrational states of the target species has been measured. The results are interpreted in terms of a model involving the compensation of deflections produced by attractive and repulsive potentials at distances larger than the potential minimum of the N⁺-N₂ system. No ``selection rule'' for vibrational energy transfer such as has been observed for N₂ ⁺ on N₂ is found.