Classification of Fe XI to XV emission lines from 3s23pn-3s 3pn+1and 3pn-3pn-13d transitions and isoelectronic spectra in manganese, chromium and vanadium

Nearly 170 emission lines of Fe X to XV, Mn X to XIV, Cr X to XII and VIX to X, which result from 3s 2 3p N -3s 3p N+1 and 3p n -3p n-1 3d transitions are classified. Of particular interest are the extensions to the analysis of the spectra of Fe XII and Fe XIII. The analysis of these transitions is complete apart from lines which are probably absent from recorded spectrograms due to their low intensities; these low intensities are predicted. The new identifications account for about twenty lines in the solar spectrum near 200 AA and 300 AA. The wavelengths of these transitions enable the calculation of the 3s 2 3p n energy levels and hence provide a direct check on the identity of forbidden lines which decay from these levels. Solar forbidden lines of Fe XI to XIII confirmed include some present in recently acquired solar ultraviolet spectra recorded with a rocket borne spectrograph during a solar eclipse.