Charge transfer between helium ions and metastable neon

Absolute and relative cross sections were obtained for the charge-transfer reaction He+(1S) + Ne* → He/sup double-dagger/ + Ne+. The Ne* represents a composite of Ne(3s 3P2) and Ne(3s 3P0), and the He/sup double-dagger/ represents various excited states of He. The studies were made by a merging-beams technique for a relative kinetic energy W of the reactants from 0.1 to 500 eV. The data indicate that the reaction is directed with most of the product Ne+ scattered in the direction of the reactant Ne*. The cross section monotonically increases with W. The threshold for the reaction is near 0.1 eV. A modified Demkov approach is used to calculate cross sections, which agree very roughly with the experimental values above W approx. = 3 eV. At lower W the agreement is poor