Partial charge transfer of doubly charged ions

Measurements of the partial charge transfer cross-sections for doubly charged ions X 2+ + Y → Y + + X + are described for C 2+ , N 2+ , A 2+ in He, Ne, A, and the results are discussed in terms of divergence from near-àdiabatic conditions caused by the crossing of potential energy curves. The single endothermic case C 2+ in He behaves adiabatically; all the others, which are exothermic, show large cross-sections at low energies. In the case A 2+ in A there is a contribution from double charge transfer, which cannot be distinguished experimentally from partial charge transfer.