The spectrum and term system of S VIII

The spectrum of seven times ionized sulfur, S VIII, has been observed in the wavelength range 50-1200 Å. Both beam-foil and laser-producedplasma light sources have been used. 71 new lines representing the transitions 2p⁵-2p⁴3d, 2p⁴3s-3p, 3p-3d, 3d-4f, 4f-5g and 5g-6h have been identified and 100 energy levels, of which 46 are new, are now accuratelyestablished. The spectral analysis is supported by isoelectronic comparisonsalong the F I-sequence and by parametric least-squares fits of Slater integrals to the observed levels. The ionization potential in S VIII is determined to 2651899 ± 60 cm^-1and estimated ionization energies arederived for the isoelectronic elements between FI and Ar X.