Identification of new electronic levels in the holmium atom and investigation of their hyperfine structure

In this work the hyperfine structure of some tens of unclassified spectral lines in the holmium atom was investigated with the method of laser induced fluorescence in a hollow cathode discharge lamp. As a result, 21 new electronic odd-parity levels, with previously unknown energies within the range 33000–42000 cm − 1 , were identified and their hyperfine structure constants A and B were determined. The experimental data obtained will facilitate the semi-empirical fit of the fine and hyperfine structure of the odd-parity level system for the atomic holmium, currently in progress in our group.