Elementary Processes Involving Rydberg Atoms and Neutral Particles: Effects of Electron-Projectile Interaction

Abstract

In this chapter our attention will be focused on further development of the theory of collisions between the Rydberg atoms and neutral particles (atoms and molecules) and its application to studies of various types of bound-bound and bound-free transitions. We shall consider different processes of excitation, de-excitation, and ionization of the highly-excited atomic states in both the weak- and strong- coupling regions. However, as in the preceding chapter, we consider here situations in which these processes are due to the mechanism associated with the scattering of a Rydberg electron on the target atom or molecule. The main emphasis will be put on the detailed description of the total and orbital angular momentum transfer processes, the inelastic transitions with a change in the principal quantum number since they were the subject of intensive experimental and theoretical research. We shall present a careful analysis of the dependence of cross section behavior on the principal quantum number, relative velocity of colliding particles, and the inelasticity parameter of one or another process. The final formulas will be given in the form convenient for specific calculations. A considerable part of this chapter is devoted to comparison of the theoretical results with available experimental data on quenching and ionization of Rydberg atomic states by the ground-state rare gas and alkali-metal atoms as well as by the polar, nonpolar, and electron-attaching molecules.