Probing Quantum Electrodynamics in Strong Fields

At the heavy-ion storage ring ESR, the effects of quantum electrodynamics (QED) can be studied even for hydrogenlike high-Z ions. In the strong fields of high-Z systems, higher-order QED effects can be investigated which are not accessible for low-Z ions. The goal of the experiments is to probe these higher-order QED contributions and to provide a stringent test of bound state QED.