Experimental investigation of the hyperfine structure of Tm I with Fourier transform spectroscopy part b: In the NIR wavelength range from 700 nm to 2250 nm

Abstract

In this study, we investigated the hyperfine structure of 43 spectral lines of atomic thulium. We analyzed Fourier-transform spectra in the wavelength range from 700 nm to 2250 nm, which corresponds to the wavenumber range from 14300 cm?1 to 4440 cm?1, respectively. The excited thulium atoms were generated in a hollow-cathode lamp. As a result of this investigation, the magnetic-dipole hyperfine constant A of 17 fine structure levels have been determined experimentally, 14 of them for the first time. The magnetic-dipole hyperfine constant values of the three remaining levels, reported in the literature, differed significantly from the results of our determination. © 2022 Elsevier Ltd