The Magnetic Dipole Transition in Rb-like Ion and Its Core-Valence Correlation Effect

This study presents both experimental and theoretical analysis of the 4d 2 D5/2 → 2 D3/2 magnetic dipole transition in Rb-like ions. Spectral lines of Xe17+, La20+ and Pr22+ ions were recorded using an electron beam ion trap. The theoretical framework employed the fully relativistic Multi-configuration Dirac–Hartree–Fock method, accounting for the Breit interaction, QED effects and comprehensive core-valence correlation. An impressive correlation is observed between the theoretical and experimental findings. Notably, this study illustrates that the contribution of the core-valence correlation, especially concerning deep core subshells, is pivotal for the fine structure splittings.