Systematic investigations of the hyperfine structure constants of Niobium I levels. Part IV: New results derived from Fourier-transform spectra, including the discovery of four new levels

Abstract

A determination of the hyperfine structure constants of high lying energy levels of the Niobium (Nb) atom was performed using Fourier-transform spectra. The results obtained complete previous investigations using mainly laser spectroscopy [JQSRT (2020) 245, 106871, 106872, 106873]. In the present work, the hf constants A of altogether 144 levels could be determined, among them 55 levels for which these constants are reported for the first time. Now for nearly all known energy levels of atomic Nb the hyperfine constants A are available. Further the discovery of four previously unknown energy levels is reported.