ASTROPHYSICAL JOURNAL, vol.970, pp.1-12, 2024 (SCI-Expanded)
The hyperfine structure of 40 spectral lines of singly ionized thulium (Tm II) in emission spectra from a hollow
cathode discharge lamp measured with a Fourier transform spectrometer in the wavelength range from 335 to
2345 nm has been investigated. As a result of the analysis, the magnetic dipole hyperfine structure constants A
for 27 fine structure levels of Tm II were determined for the first time. In addition, the values of two magnetic
dipole hyperfine structure constants A from the literature were declared incorrect, and the corrected values were
given.