Hyperfine Structure Investigations of Mn I. Part I: Experimental and Theoretical Studies of the Hyperfine Structure in the Even Configurations

Optogalvanic laser spectroscopy has been applied to measure the hyperfine structure of 12 spectral lines of Mn I in the wavelength regions of 660–645 nm and 933–911 nm. Experimental hyperfine structure constants A and B of the isotope 55 Mn have been determined for seven levels of even and seven levels of odd parity. Additionally, a parametric analysis of the fine structure and the magnetic dipole hyperfine structure has been performed for the three even configurations 3d 5 4s 2 , 3d 6 4s and 3d 7 . Very large values for the ratio a 3d 10 / a 3d 01 are found. Theoretical predictions for the magnetic dipole hyperfine structure constants A for all levels of the configurations 3d 5 4s 2 , 3d 6 4s and 3d 7 are given.