The magnetic dipole transition in Rb-like ion and its core-valence correlation effect

This study presents both experimental and theoretical analysis of the 4d2D5/2→2D3/2 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. •Spectra of 4d2D5/2→2D3/2 transitions in Xe17+, La20+ and Pr22+ were observed at a compact EBIT.•An MCDHF FCV model with Breit and QED corrections predicts the energies within high accuracy.•Deep CV correlation effect is significant on the 4d fine structure splitting in Rb-like ions.