Principal quantum number dependence for electron-alkali atom scattering

Over the last two decades, there has been considerable interest in the electron-atom scattering problem. Most of this work has concentrated on elastic scattering and excitation of the lowest energy states. However, due to recent technological advances, it is now becoming possible to examine the excitation of higher states experimentally. The important question then concerns whether these higher states contain new information. We have recently examined the N dependence for electron-hydrogen scattering. The purpose of this work is to examine the N dependence for electron scattering from alkali atoms. The second-order distorted-wave method has been used to calculate scattering amplitudes for excitation of the higher lying levels of Li, Na and K atoms up to N = 7. The N dependence of the differential cross section and angular correlation parameter are discussed for energies from threshold to 250 eV. (Author)