Dielectronic recombination of very heavy lithiumlike ions

An overview of measurements of dielectronic recombination (DR) with the heaviest lithiumlike ions is presented. The experiments have been carried out at the heavy ion storage ring ESR at GSI utilizing the electron cooler as an electron target. In particular, results for low energy dielectronic recombination of Au76+ and U89+ are discussed. In the energy range of 0 to 400 eV which can be covered with our present set-up dielectronic resonances associated with Deltan = 0 core excitations from 2s(1/2) --> 2p(1/2,3/2) were found. The experimental results can only be explained within a fully relativistic treatment and are sensitive to QED contributions of the order alpha(2) as well as to the finite size of the atomic nucleus.