Isotope shift studies in the spectral lines of Yb I in the 3405–4365-Å region and term shifts of some odd- and even-parity energy levels

Isotope shifts, Δσ (172Yb–176Yb), in 29 spectral lines of neutral ytterbium (Yb I) are reported in the region 3405–4365 Å. Earlier measurements in this region are available for five lines. The present measurements of isotope shift were carried out using the photoelectric recording Fabry–Perot spectrometer and highly enriched isotopic samples of 172Yb and 176Yb. Term isotope shifts, ΔT (172Yb–176Yb), have been evaluated for 19 even and five odd parity high lying energy levels of Yb I, and the configurations assigned to these levels are discussed.