EXTENDED ANALYSES OF 6-TIMES IONIZED SELENIUM (SE-VII) AND 7-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 incid ence spectrograph. The source used was a triggered spark. The Se VII a nd 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 S e VII and all levels of the 3d(9)4f and 3d(9)5p configurations of Br V III have been established. Out of 90 possible levels of the three open shell configuration 3d(8)4s4p, 39 levels were identified in Se VII an d 37 levels in Br VIII. 226 new lines in Se VII and 177 new lines in B r VIII have been classified. The least-squares-fitting parametric calc ulations and Hartree-Fock ab-initio calculations involving configurati on interaction were caried out for both ions and they reproduce the ob served spectra quite adequately.