Magnetic dipole lines of Sc-like Kr15+ and Br14+ ions.

In this paper, we report on optical lines of Sc-like Kr 1 5 + and Br 1 4 + observed using a low-energy electron beam ion trap. Within the spectral range of 220–590 nm, a total of 18 spectral lines from these two ions were identified, 12 of which were reported for the first time. To determine the energy levels, the multi-configuration Dirac–Hartree–Fock method and relativistic many-body perturbation theory are employed. The excitation energies for the 19 lowest levels arising from 3 d 3 ground configuration of Kr 1 5 + and Br 1 4 + ions are presented. Comparing the theoretical wavelengths with the experimental values, a good agreement is observed with an average deviation of less than 1.1%. However, for a few lines, discrepancies larger than 2.0% are observed. The present experimental results could be reference data for further theoretical investigations of the multi-valence electron ions. [ABSTRACT FROM AUTHOR]