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