Principal Quantum Number Dependence for Electron–Hydrogen Collisions

Abstract

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 experimentally the excitation of higher lying states. The important question then concerns whether these higher states contain new information. It has been argued that the scattering amplitudes for electron–helium excitation should scale with principal quantum and thus contain no new information. The purpose of this work is to examine the n-dependence for electron–hydrogen scattering. The converged-close-coupling and second-order distorted–wave methods have been used to calculate scattering amplitudes for excitation of the n = 2, 3 and 4 levels of the hydrogen atom. The n-dependence of the integrated cross sections, differential cross sections and angular correlation parameters will be discussed for energies from threshold to 500 eV.