Absolute Term Energies of Core-Excited Doublets of Li I Determined Experimentally

We report four new observations of transitions within the core-excited doublet system of Li I. Absolute term energies for eight doublet states in the system have been determined at an accuracy better than 10 cm -1 . The energy scale was established from the recent experimental term energy of the 1 s 2 s 2 p 4 P 0 state of Mannervik and Cederquist combined with the wavelength for the laser-induced intercombination transition 1 s 2 s 2 p 4 P 0 – 1 s 2 p 2 2 P recently observed by Willison et al. In this context also isotope shift and mass polarization had to be considered. The present experimental absolute term energies are compared with recent theoretical and experimental results.