Interference effects in electron-ion recombination. III. Excited target states and continuum-continuum coupling.

Abstract

Provision is made for the existence of excited target states and projectile continuum-continuum coupling, within the framework of the interacting resonance theory of electron-ion recombination described previously (Phys. Rev. A 36, 4662 (1987); 38, 1820 (1988)). This ''extended'' theory makes explicit what was merely implicit in these earlier works. Dielectronic recombination probabilities, which include the effects of interaction and interference between resonances, are derived for two model systems: (a) A target ground state supporting two coupled projectile continua, and one excited target state as a closed channel; (b) a ground and first excited target state, each supporting one projectile continuum, and a second excited target state as a closed channel. Explicit calculations are performed for model (b), wherein are included Rydberg series of fully interacting resonances built on each of the two excited target states. The probability of excitation from the ground to the first excited target state is also obtained for model (b). This probability includes the effect of the interaction and interference between resonances, as well as the interference between resonance and direct excitation processes.