Analysis of the sixth spectrum of barium: Ba VI

The spectrum of barium was photographed in the 300 Å-1240 Å wavelength region on a 3-m normal incidence spectrograph at the Antigonish laboratory. The source used was a triggered spark. All five levels of the ground configuration 5 s 2 5 p 3 and 42 of 44 levels of the 5 s 5 p 4 + 5 s 2 5 p 2 5 d + 5 s 2 5 p 2 6 s configurations of Ba VI have been established. One hundred and twenty-seven lines have been classified. The parametric least-squaresfitted calculations involving configuration interaction amongst even parity configurations were carried out to interpret the observed spectrum satisfactorily.