Eikonal Theory of Inelastic Electron-Atom Scattering at Intermediate Energies

An eikonal distorted-wave theory is proposed for inelastic electron-atom collisions at intermediate energies. The primary interaction, responsible for the transition, is treated to first order, while the initial- and final-state interactions are taken into account by using the eikonal approximation. Direct and exchange collisions are both considered. Detailed numerical calculations are performed for the excitation of the $n=2$ levels of atomic hydrogen by electron impact. The results for the differential excitation cross sections are compared with those obtained in the Glauber eikonal approximation at small scattering angles.