The spectrum of selenium has been observed in the wavelength region 1200–100 Å on the 10.7 m normal incidence and 10.7 m grazing incidence vacuum spectrographs at the NBS Laboratory in Washington. A triggered vacuum spark was used as a source. The “pole effect” exhibited by the lines on the normal incidence spectrograms helped to discriminate different stages of ionization of the selenium spectra. All the levels belonging to the 3d94s and 3d94p configurations in Se VII have been located. The parametric level fitting calculations of the energy levels agree with the experimental values. In Se VIII, the 3p53d102P° term has been determined.
© 1977 Optical Society of America
Th. A. M. vanKleef and Y. N. Joshi, "Seventh spectrum of selenium: Se VII and the 3p53d10 configuration in Se VIII," J. Opt. Soc. Am. 67, 472-475 (1977)