Charge transfer in collisions of H2+ ions with He2+ and Ar2+

Using the crossed-beams technique, we have measured absolute total cross sections for electron capture from H2+ molecular ions by He2+ and Ar2+ at relative velocities vrel = 0.7-1.3 au. With He2+ a distinct maximum around vrel = 1 au is observed, which can be attributed to the large Q-value for the dominant channel of this reaction. Theoretical calculations using an atomic model for ion-molecule collisions are in very good agreement with the experimental data.