Line strengths of QED-sensitive forbidden transitions in B-, Al-, F- and Cl-like ions

Abstract

The magnetic dipole (M1) line strength between the fine-structure levels of the ground configurations in B-, F-, Al- and Cl-like ions are calculated for the four elements argon, iron, molybdenum and tungsten. Systematically enlarged multiconfiguration Dirac-Hartree-Fock~(MCDHF) wave functions are employed to account for the interelectronic interaction with the Breit interaction included in first-order perturbation theory. The QED corrections are evaluated to all orders in $\alpha Z$ utilizing an effective potential approach. The calculated line strengths are compared with the results of other theories. The M1 transition rates are reported using accurate energies from the literature. Moreover, the lifetimes in the range of millisecond to picoseconds are predicted including the contributions also from the transition rate due to the E2 transition channel. The discrepancies of the predicted rates from those available from the literature are discussed and a benchmark dataset of theoretical lifetimes is provided to support future experiments.