Spectrum and Energy Levels of Mg-like Br XXIV

Abstract

The spectrum of Mg-like Br, Br XXIV, was investigated by means of the beam-foil technique. Bromine ions of 90 and 130 MeV energy from the HI-13 tandem accelerator at the China Institute of Atomic Energy were used, and the wavelength region 130–290 Å was investigated. The spectra showed 24 Br XXIV transitions within the n = 3 complex, i.e. between the 3s2, 3s3p, 3p2, 3s3d and 3p3d configurations. Of these 5 have been reported earlier. In this spectrum 19 energy levels have now been experimentally determined, 14 of which have not been reported earlier. The observed energy level values have been theoretically interpreted by means of relativistic Hartree-Fock (HFR) calculations.

Fine-structure energy levels and lifetimes in Br XXIV

“…These experimental values they derived fitting their transition wavenumbers by means of a least-squares procedure, using the computer program ELCALC (Radziemski et al 1973). In general our ab initio calculation, denoted as 'Present (a)', is in good agreement with the experiment Zeng et al (2000). In order to keep our ab initio energies as close as possible to the experimental values, we have made small J-dependent adjustments to the diagonal elements of the Hamiltonian matrices.…”

“…Our adjusted theoretical energies, 'Present (b)', are also listed in table 2 and are in much better agreement with the experiment. In this table, we interchanged the relative positions of the energy levels of the states 3p 2 ( 1 D 2 ) and 3p 2 ( 3 P 2 ) in the experimental results (Zeng et al 2000). With this interchange, most of our results, including their ordering, agree better than 1.0% with the experimental data.…”

“…In table 2, our calculated fine-structure excitation energies relative to the ground level are compared with the experimental results of Zeng et al (2000). These experimental values they derived fitting their transition wavenumbers by means of a least-squares procedure, using the computer program ELCALC (Radziemski et al 1973).…”

“…The spectra of these ions have been extensively studied (Litzen and Redfors 1987, Seely et al 1988, Sugar et al 1989, Ekberg et al 1989, Churilov et al 1989 mostly using laser-produced plasma and fusion plasma. Zeng et al (2000) using beam-foil excitation technique, investigated the transitions and energy levels in Br XXIV.…”

Extended line identification for Ne-like GeXXIII

“…The present experiment was performed at the China Institute of Atomic Energy (CIAE) using the beam-foil method. It is similar to recent studies of Br XXIV by Zeng et al (2000) and of Br XXVI by Jupén et al (2000). The experimental facility includes a HI-13 13 MV Tandem Van de Graaff accelerator and a 2.2 m grazing incidence GIM-957 XUV monochromator (built at CIAE).…”