Isotope shift and hyperfine structure in even configurations of neutral europium

Abstract

Results of the measurements of the isotope shifts, as well as the hyperfine structure constants, are presented concerning electronic levels belonging to the even configurations in a europium atom with energies within the range 28 000–43 000 cm−1. The data were obtained with the method of laser-induced fluorescence in a hollow-cathode discharge. On the basis of the measurements of 137 spectral lines, the values of isotope shifts and hyperfine structure constants A and B for 69 levels were determined; in the case of 44 levels, these values were obtained for the first time. Relying on the experimental results, the parameters describing the isotope shifts for individual configurations and the crossed second-order effects were calculated. The results obtained were compared to the ab initio estimations.