Structure of hydrogenic transitions in high-Z beryllium-like ions☆

Abstract The structure of hydrogenic states, or low lying Rydberg states, in highly-ionized beryllium-like atoms is influenced by the effects of atomic core polarization as well as configuration interaction. Measurements have been made, using fast-ion spectroscopy, of the resolved structure of hydrogenic transitions in S XIII and Cl XIV involving 1s 2 2s nl and 1s 2 2p nl states with n = 6–11. Relativistic MCHF calculations are compared with the observed structures.