  The charge transfer reaction of Ar+ with H2 and D2 has been investigated in
an experiment combining crossed beams with three-dimensional velocity map
imaging. Angle-differential cross sections for two collision energies have been
obtained for both neutral species. We find that the product ions are highly
internally excited. In the reaction with H2 the spin-orbit excited Ar+ state's
coupling to the 'resonant' vibrationally excited product H2+(v=2) dominates for
both investigated energies, in line with previous investigations. The observed
angular distributions, however, show significantly less back-scattering than
was found previously. Furthermore, we discovered that the product ions are
highly rotationally excited. In the case of Ar+ reacting with D2 the
energetically closest lying vibrational levels are not strictly preferred and
higher-lying vibrational levels are also populated. For both species the
backward-scattered products show higher internal excitation.
