MPMC - Sorbonne Université - 4 place Jussieu, 75005 Paris, tour 23, 4e étage, couloir 22-23, salle 401
Alexandre Gumberidze - GSI Helmholtzzentrum für Schwerionenforschung (Darmstadt, Allemagne)
Abstract
Highly charged ions (HCI) combine extremely strong electromagnetic fields and a simple electronic structure, which makes them ideal testing grounds for fundamental theories such as quantum mechanics, relativity and quantum electrodynamics (QED) in the domain of strongest electromagnetic fields available for experimental investigation. In the heaviest few-electron ions, such as hydrogen-like uranium (U91+), the field strength exposed on the electron in the ground-state is already close to the Schwinger limit ; the field strength in which a spontaneous electron-positron pair creation can occur. Therefore, the structure of highly-charged ions is strongly influenced by the effects of the quantum vacuum. In addition, precision studies of HCI provide access to nuclear properties, such as size, magnetic moment, isomeric states etc. In the recent decades there has been a substantial progress both in theoretical as well as experimental investigations of HCIs.