A NEW MULTIPLET TABLE FOR FE-I

We have recorded spectra of iron-neon and iron-argon hollow cathode lamps in the region 1700 angstrom-5 mum (59,000-2000 cm-1), with Fourier transform (FT) spectrometers at the National Solar Observatory, Tucson, Arizona, and Imperial College, London, UK, and with a high-resolution grating spectrograph at the National Institute of Standards and Technology, Gaithersburg, Maryland. The uncertainty of the strongest lines in the FT spectra is less than 0.002 cm-1 (0.2 mangstrom at 3000 angstrom; 8 mangstrom at 2 mum). Pressure- and current-dependent shifts are less than 0.001 cm-1 for transitions between low-lying levels, increasing to 0.006 cm-1 for transitions between the most highly excited levels. We report 28 new energy levels of Fe I and revised values of another 818 levels. We have identified 9501 lines as due to 9759 transitions in Fe I, and these are presented in the form of a new multiplet table and finding list. This compares with the approximately 5500 lines due to 467 energy levels in the multiplet tables of Moore (1950, 1959). The biggest increase is in the near-ultraviolet and near infrared, and many of the new lines are present in the solar spectrum. Experimental log (gf) values are included where they are available. A further 125 unidentified lines due to Fe I are given. The tables are also available in computer-readable form.