Current theoretical techniques for electron-atom and electron-ion scattering

This chapter considers excitation processes from a target in a state /i> to a final state /f>. Explains that if the initial state /i> is the ground state /O>, then provided the energy of the incident electron is less than the ionization potential of the target I /SUB x/ . The first choice is an eigenfunction expansion method. Conversely, if the incident energy is many times I /SUB x/ , the choice is the First Born Approximation (FBA), provided an overall spin change is not involved, or in the case of positive ions, the Coulomb Born Approximation (CBA). Discusses eigenfunction expansion methods, distorted wave approximations, excitation of positive ions near threshold, excitation of positive ions by fast electrons, and electron impact ionization of positive ions