Precision measurements with highly charged ions at rest: The HITRAP project at GSI

A decelerator will be installed at GSI in order to provide and study bare heavy nuclei or heavy nuclei with only few electrons at very low energies or almost at rest. Stripping at relativistic energies will produce highly charged ions. After electron cooling and deceleration in the experimental storage ring the ions are extracted from the storage ring at 4 MeV/u and further decelerated in a combination of an IH and four-rod RFQ structure. Finally, they are injected into a Penning trap where the ions are cooled to 4 K. From this cooler trap, the ions can be transferred in a quasi-continuous or pulsed mode to different experimental setups. High-precision measurements of electronic and nuclear binding energies will be performed in a Penning trap exploring the high charge states. Other key experiments focus on g-factor measurements of the bound electron, precision laser and X-ray spectroscopy, studies of ionic structure, hollow atoms, and ion-surface interaction at very low impact energies.