Investigation of the Hyperfine Structure of Atomic Niobium (Nb I) Spectral Lines Based on the Lower Energy Levels at 22936, 23010, and 23048 cmsup-1/sup

摘要

The hyperfine (hf) structure constants of three atomic niobium energy levels in the energy range around 23000 cm-1 (at 22936.90, 23010.58, and 23048.58 cm-1) are known with only limited accuracy, and the constants of combining levels are sometimes even unknown. Thus we performed laser spectroscopic investigations in the wavelength range between 5600 and 6500 Å, and we excited altogether 16 transitions in which these lower levels are involved. Beside a more precise determination of the hf structure constants of the three lower levels (which were determined on several lines sharing a common upper level), these experiments led to the knowledge of the hf constants of nine levels with previously unknown constants. Beside these results, also the hf constants of 13 further energy levels are reported. For six of these levels, the constants were previously unknown.