Identification of intercombination transitions in FE XIV and Fe XIII in the spectra of foil-excited ions and solar flares

Prompt and time-delayed beam-foil spectra of iron in the VUV region have been recorded, using 24 MeV ions of Fe. The time-delayed spectra, observed 17 ns after excitation by the foil, showed intercombination lines in Al-like Fe XIV and Si-like Fe XIII which have not been classified earlier. The identifications are supported by lifetime measurements, studies of isoelectronic regularities and comparisons with theoretically predicted data. The measured wavelengths coincide with those of some unidentified transitions, observed in high-resolution spectra of solar flares. The solar data are used to obtain accurate information on the excitation energies of the quartet and quintet term systems in Fe XIV and Fe XIII, respectively. (author)