Electron scattering from atoms within a laser field: Green's function method

Abstract

The generalization of Kroll and Watson's theory for electron scattering accompanying multiphoton absorption (emission) is attempted from the field theoretical viewpoint. In our theory, the simple static potential is replaced with the optical potential (or self-energy) in the presence of a radiation field. In addition to the “elastic” electron scattering which has been treated previously the “inelastic” electron scattering accompanying multiphoton transfer will be discussed and the S matrices for both the “elastic” and “inelastic” scattering processes will be derived. As to the single-photon processes, the S-matrices for simple free—free transition, superelastic scattering, and electron—photon cooperative excitation will be derived.