PHYSICA SCRIPTA, cilt.71, sa.2, ss.159-162, 2005 (SCI-Expanded)
High resolution laser spectroscopy has been applied to study the hyperfine structure of excited levels of Tm 1. In the wavelength range from 570 nm to 595 nm 31 transitions were measured using a hollow cathode discharge and a tunable single mode cw ring dye laser. Precise values for the magnetic dipole hyperfine structure constants A of 24 even and 19 odd levels were determined.