Strong Field Effects on the Structure and the Dynamics of High-Z Ions

Institut fuer Kernphysik, University of Frankfurt and GSI-Darmstadt

In a high-Z one electron system such as hydrogen-like uranium, the ground state electron experiences a mean field of up to 2x10¹⁶ V/cm. In such strong fields, the atomic structure is dominated by relativistic effects and is considerably influenced by quantum-electrodynamics. Here, higher-order QED effects can be investigated which are not accessible for low-Z ions. The goal of the experiments currently performed at the heavy-ion storage ring ESR is to probe these higher-order QED contributions for high-Z one electron systems and to provide a stringent test of bound state QED. Furthermore, the collision dynamics of high-Z ions can be studied at the ESR where the magnetic effects induced by both, the relativistic motion and the strong central fields of the projectiles are of particular interest. As an example, these experiments allowed to identify spin-flip contributions for the time reversed photoionization process which are not accessible in direct photoionization studies for neutral high-Z atoms.