Seventh spectrum of lanthanum: La VII

The spectra of lanthanum ions were photographed in the 90 Angstrom-1220 Angstrom region on a 3-m normal incidence spectrograph at the Antigonish laboratory and a 10.7 m grazing incidence spectrograph at the MST laboratory. The source used in both laboratories was a triggered spark. The 5s(2)5p(3)(5s5p(4) + 5s(2)5p(2)5d + 5s(2)5p(2)6s) transitions of La VII were analysed. All five levels of the ground state and 37 of 44 levels of the 5s5p(4) + 5s(2)5p(2)5d + 5s(2)5p(2)6s configurations have been established 102 lines have been classified in the 307-1005 Angstrom region. Hartre-Fock (HFR) and Least-Squares-Fit (LSF) calculations were carried out to interpret the spectrum.