Extended analyses of six-times ionized selenium (Se VII) and seven-times ionized bromine (Br VIII)

The spectra of selenium and bromine ions were photographed in the 100-1250 Angstrom region on a 2-m grazing incidence and a 3-m normal incidence spectrograph. The source used was a triggered spark. The Se VII and Br VIII spectra have been analysed. The earlier identifications of the 3d(10) S-1(0)-3d(9)5p (J = 1) have been completely revised in both spectra. All levels of the 3d(9)5s, 6s, 4f and 5p configurations of Se VII and all levels of the 3d(9)4f and 3d(9)5p configurations of Br VIII have been established. Out of 90 possible levels of the three open shell configuration 3d(8)4s4p, 39 levels were identified in Se VII and 37 levels in Br VIII. 226 new lines in Se VII and 177 new lines in Br VIII have been classified. The least-squares-fitting parametric calculations and Hartree-Fock ab-initio calculations involving configuration interaction were caried out for both ions and they reproduce the observed spectra quite adequately.