Continuum processes in many-electron atoms

Abstract

A detailed understanding of the physics of electron-atom and photon-atom collisions has been of use in many fields of application such as astrophysics, plasma physics and controlled thermonuclear fusion, laser physics, isotope separation, and surface science. Experiments have sought to reveal details of the dynamics of a myriad of processes at a fundamental level. In this chapter, we examine several topics in which a relativistic formulation is desirable. Low-energy elastic scattering of electrons by heavy atoms was one of the earliest of these to be investigated. At slightly higher energies, multi-channel close-coupling methods have been popular, and we focus on relativistic generalizations of the popular R-matrix method, both for electron-atom scattering and for photo-excitation and ionization, as well as the relativistic random phase approximation.