Recombination of Ions in a Coulomb Field in the Presence of a Scavenger

The method of ``matched perturbation solutions'' is used in an analytical treatment of the recombination of a pair of ions in the presence of a scavenger. The perturbation series contains terms in integral powers of $c_8^{\text{1/2}}$ and the solution presented here is carried out explicitly to the term in c_s. This solution gives the effect of scavenger on recombination rigorously for small scavenger concentrations. It agrees with prescribed diffusion in the $c_8^{\text{1/2}}$ term.