Low energy charge-transfer collisions of rare gas dications: Ne2+ + Ne and Kr2+ + Kr

We report measurements of the double charge transfer reactions Ne2+ + Ne → Ne + Ne2+ and Kr2+ + Kr → Kr + Kr2+ at hyperthermal energies. At collision energies below 0.8 eV, the experimental results are well reproduced by the capture (Langevin) cross section multiplied by the factor 1/2. For the single charge transfer channel, Ne2+ + Ne → Ne+ + Ne+, our experiment suggests that the process has a very small cross section.