Abstract
Cross sections have been calculated for electron-impact ionization of singly excited states of the rare gases (neon, argon, krypton, xenon), cadmium, and mercury. The calculations are based upon the symmetric binary-encounter model, together with a semiempirically determined momentum distribution function for the bound, excited electron. Good agreement is obtained with the available experimental data, as well as with existing theoretical results, in the low- to intermediate-energy range.