The optically thick Fe XVII spectrum: X-ray, extreme-ultraviolet and forbidden line ratios

Level populations, X-ray line fluxes, and extreme-ultraviolet (EUV) line in tensities are calculated for a 37 level model of the Fe XVII ion, as functi ons of the column density of Fe XVII, in slab geometry and cylindrical geom etry. The resonance lines at 15.02 and 15.25 Angstrom are found to exhibit initial increases in fluxes relative to the forbidden line at 17.10 Angstro m and the usual reference resonance line at 16.78 Angstrom as optical thick ness increases. Eleven EUV lines and the forbidden 2p(5)3s(P-3(0)-P-3(1)) t ransition near 1154 Angstrom are also found to be relatively enhanced by op acity.