Beyond Dipole Effects in Atomic Processes

L. A. LaJohn and R. H. Pratt

Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260

Abstract:

We attempt to answer the question: to what extent does physics beyond the nuclear point Coulomb level enter into observable properties of non-dipolar matrix elements in atomic processes such as photoionization, Rayleigh scattering and bremsstrahlung? We characterize these processes in terms of nuclear point Coulomb properties plus low multipole screening contributions. Except in photoeffect, the atomic form factor is also needed. In photoionization no higher than octupole, in Rayleigh scattering no more than quadrupole, screening contributions need to be included to achieve accuracy within a few percent. Similar considerations apply to bremsstrahlung.