Electron capture and dissociation of the N2q+ molecule in slow Ar8+/N2 collisions

Single and multiple electron capture processes are studied in slow (8-16 keV) collisions between Ar8+ and molecular nitrogen. The contributions of dissociative and non-dissociative channels are determined as well as the kinetic energies of the fragments of the N2q+ (q = 1-6) ions. From the kinetic energies of the fragments dissociation energies of the N2q+ molecular ion are deduced. Under the assumption of isotropic dissociation the following results are obtained: at most 7% of single-electron capture leads to dissociation of N2+ into N + N+ and at least 90% of the double-electron capture results in fragmentation into N+ + N+. If more than two electrons are captured, all N2q+-ions dissociate into Nr+ and Nst. For even values of q we observe r = s, otherwise r = s ± 1; i.e. the maximum difference between r and s is 1. A charge distribution closest to the most symmetric one is preferred. (author)