Improved experimental energy levels of carbon I from solar infrared spectra

We have improved the energy levels in neutral carbon using high resolution infrared solar spectra. The main source is the space-based ATMOS spectrum measured by the Fourier transform spectroscopy technique from 600 to 4800 cm-1. From these infrared data, we have determined 19 new energy levels in the 5f, 5g, 6g and 6h configurations. To extend measurements to higher frequencies, we also use other FTS solar spectra: the MARK IV balloon data, covering from 4700 to 5700 cm-1, and the ground-based NOAO spectra, up to 9000 cm-1 of Livingston and Wallace and 8900 to 13 600 cm-1 of Wallace et al. For completeness' sake, we include the 63 new levels found by Feldman et al. plus 8 new levels derived from the VUV data. Utilizing all existing carbon spectra from the far infrared to the vacuum ultraviolet, we have revised Johansson's energy levels and the ionization potential, resulting in improving the accuracy by about an order of magnitude to about 3 mK. (orig.)