Spin-orbit coupling photoionization

Abstract

Dirac-Slater calculations are used to predict the ratio of photoionization cross sections for the j=l+or-1/2 components of an atomic orbital. It is shown that the ratio is larger or smaller than the statistical value of l+1:l depending on whether the partial cross section is rising or falling. Two effects are shown to determine the deviation from the statistical ratio, one arising from small differences in the bound state orbitals, and the other from differences in the kinetic energy of the photoelectrons. Differences between the asymmetry parameter, beta , for the two ionizations are found to be small except at the Cooper minimum. In general the primary cause of the two values of beta not being the same at low photoelectron energies is the kinetic energy effect.