Electron-ion collision spectroscopy at the ion-storage rings of FAIR

The technical goal of this project is to provide a novel flexible infrastructure for electron-ion collision experiments at the FAIR ion-storage rings ESR, CRYRING and HESR. Electron-ion collisions are an important and established tool for atomic precision spectroscopy with a wide range of applications. The low-energy storage ring CRYRING in combination with heavy ions injected from SIS18 and ESR offers world-unique possibilities for precision experiments with highly charged ions. Already in the FAIR phase-0, this potential will be exploited using the CRYRING electron-cooler for electron-ion collision spectroscopy of few-electron highly-charged ions addressing the atomic structure and collision dynamics in strong fields. In addition, a separate transverse electron target will be installed at CRYRING which will provide access to a wider range of electron-ion collision experiments.