Abstract
Fully relativistic calculations are presented for the double -shell photoionization cross section for several neutral medium- atoms, from magnesium () up to silver (). The calculations take into account all multipoles of the absorbed photon as well as the retardation of the electron-electron interaction. The approach is based on the partial-wave representation of the Dirac continuum states and uses the Green's-function technique to represent the full Dirac spectrum of intermediate states. The method is strictly gauge invariant, which is used as an independent cross-check of the computational procedure. The calculated ratios of the double-to-single -shell ionization cross sections are compared with the experimental data and with previous computations.
- Received 19 November 2014
DOI:https://doi.org/10.1103/PhysRevA.90.063422
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