Many-Body Problems in Atomic Physics

Abstract

During the last decade a new and exciting field has opened up in atomic physics, namely the field of heavy-ion spectroscopy. Highly ionized atoms have been studied for a long time, for instance, using astrophysical light sources. More recently, however, new experimental tools have become available, such as laser-produced plasmas and plasma discharges in Tokamaks and similar devices, which make it possible to study long iso-electronic sequences, such as copper-like ions up to uranium (for a review, see, for instance, Martinsson 1989). In heavy-ion accelerators, like UNILAC at GSI in Darmstadt, GANIL in Caen and the BEVALAC at Berkeley, highly stripped ions can be produced, up to hydrogen-like uranium. Quite recently, for instance, very accurate experiments have been reported from Berkeley on Li-like uranium (Schweppe et al 1991). Here, the Lamb shift in the 2s-2p transition is about 40 eV, to be compared with the experimental uncertainty of 0.1 eV. Experimental results of this kind demonstrate the importance of developing a many-body procedure, which incorporates quantum-electrodynamic (QED) effects into the many-body formalism in a consistent way.