Zusammenfassung

The Stark effect on diamagnetic Rydberg states of hydrogen is investigated. In the perturbative regime, re-ordering of levels within a hydrogenic n manifold leads to level repulsion when the ratio of field strengths is varied. When the fields become strong enough very narrow avoided crossings between levels from different n manifolds appear. In addition the authors study the Stark effect on recently observed quasiLandau structure in the irregular part of the spectrum.