Fine- and hyperfine-structure measurements in doubly excited6,7Li I 1s2p24P

Using the zero-field quantum-beat technique after beam-foil excitation the authors determine fine-structure and hyperfine-structure parameters of doubly excited Li I 1s2P 2 4 P at 60.8 eV above the ground state from the multiplet at 3714 AA. The data interpretation uses simultaneously experimental results from both stable Li isotopes, 6 Li and 7 Li. The values for the fine-structure splittings are E 5 2/-E 3 2/=(-57+or-8) GHz E 5 2/-E 1 2/=(1.36+or-0.07) GHz. The one-electron parameters of the hyperfine structure are a s ( 6 Li)=5.58+or-0.09) GHz a 0 ( 6 Li)=(0.023+or-0.015) GHz.