New identifications of Si VIII and S x lines in the solar coronal spectrummeasured by SOHO/SUMER

This paper reports the identification of 14 lines in the solar coronal spec trum as high-excitation 2s(2)2p(2)3s-2s(2)2p(2)3p and 2s(2)2p(2)3p-2s(2)2p( 2)3d transitions in Si VIII and S x (N I isoelectronic sequence). The analy sis combines solar spectra, recorded by the SUMER (Solar Ultraviolet Measur ement of Emitted Radiation) instrument on board the Solar and Heliospheric Observatory (SOHO) satellite, with laboratory data obtained with the beam-f oil technique. Theoretical gA values and branching ratios for the observed lines, based on semiempirical calculations, are also presented. Intensity r atios between the newly identified high-excitation transitions and known fo rbidden transitions within the 2s(2)2p(3) ground configuration can be used in determining coronal plasma temperatures in the 70-120 eV range.