Investigation of the Hyperfine Structure of Ta I Lines (IX)

Abstract

We report the discovery of 25 previously unknown energy levels of even parity and 3 previously unknown energy levels of odd parity of the tantalum atom, including the last two unknown levels with energy values below 32500 cm-1. Thus, below 32500 cm-1, all levels predicted by theory have now been observed. These results are based on investigations of the hyperfine structure of 126 new spectral lines of the tantalum atom (Ta I) by means of laser spectroscopy. The observation of laser-induced fluorescence further led to the classification of 159 spectral lines. Additionally, 235 lines, observed in high resolution Fourier transform spectra, were classified by their wave numbers and their characteristic hyperfine patterns.