AB-INITIO CALCULATIONS OF QED EFFECTS IN LI-LIKE, NA-LIKE AND CU-LIKE IONS

We review ab initio calculations of the bound-state self-energy and vacuum polarization for resonant transitions of Li-like, Na-like and Cu-like ions with a degree of ionization of about ten or greater. The direct part of the Dirac-Fock potential is included to all orders in the radiative corrections, and exchange effects are added in first order. When combined with previous relativistic correlation calculations, the results agree in most cases with experiment, the most notable exception being the Cu isoelectronic sequence at low Z, where the third-order correlation calculations have probably not converged to experimental precision. For low and intermediate Z, the ''screening'' effect is found to scale closely as the normalization of the valence wavefunction at the origin, but at high Z deviations from this scaling principle can be significant.