A Detailed Analysis of the<i>n</i>=3 –<i>n'</i>=3 Transitions in the Mg-like Ions FeXV, CoXVI and NiXVII

Abstract

Laser produced spectra of iron, cobalt and nickel were obtained using the 6.65 m normal incidence vacuum spectrograph with a short-wave blazed 1200 lines/mm grating. Transitions between the configurations 3s2, 3s3p, 3p2, 3s3d and 3p3d of the Mg-like ions FeXV, CoXVI and NiXVII were studied in the region 170-600 Å. Singlet-triplet connections were found for these ions. The previous identifications were revised and 60 new lines, mainly from the 3p3d configuration, were found. Wavelengths were remeasured and related energy levels were improved. New identifications of solar flare lines are proposed on the basis of this work.