Hyperfine structure studies of the electronic levels of the manganese atom. I. Even-parity level system

Abstract In this work the hyperfine structure of 26 even-parity levels of the manganese atom was investigated with the method of laser induced fluorescence on an atomic beam. Altogether 47 spectral lines were examined, with the even-parity levels involved as the lower levels. For three levels both the constants A and B were determined for the first time, for another eight levels new constants B were obtained. The obtained results concerning the even-parity levels contributed to a considerable extension of the available database of the hyperfine structure constants for the atomic manganese. The values obtained were included in a semi-empirical analysis of the fine and the hyperfine structure for the even-parity configurations system, performed also in this work. A good agreement between the experimental and the theoretically predicted hyperfine structure constants was achieved.