A critical compilation and extended analysis of the Ne IV spectrum

Since Moore published her well-known tables of atomic and ionic energy levels (in 1949-1951), the number of observed lines of the light atoms and their ions has grown significantly. The lack of complete and consistent up-to-date tables of spectral lines and energy levels, particularly of the neon-ions spectra, notably reduces possibilities of interpretation of astrophysical and laboratory spectra. In the present paper, all optical spectral lines of Ne IV observed in 24 previous works have been systematised together with recent observations made by means of the beam-foil method at Liege University. As a result of our extended analysis of the whole set of available data, 35 new energy levels have been found and 90 newly classified spectral lines have been listed for the Ne IV spectrum, only a few of them having been reported previously. A complete table of observed and classified spectral lines has been built, and the list of optimised energy levels has been derived from it in a consistent way. A new, improved, ionisation potential of Ne IV has been deduced from the experimental data. (orig.)