The HITRAP facility for slow highly charged ions

At the GSI accelerator complex, behind the universal linear accelerator UNILAC and the synchrotron SIS, highly-charged ions up to U72+ are produced at 400 MeV/nucleon. When this beam is sent through a copper foil all or nearly all remaining electrons will be stripped; when sent through a more massive target the nuclei will fragment and produce highly charged ions of exotic nuclei. The HITRAP facility is built to decelerate those ions to almost rest and to provide them to experiments. The decelerated ions will be used for precision experiments in atomic and nuclear physics. They range from laser spectroscopy on stored ions, collision experiments with complete kinematic analysis to high precision mass measurements on single highly charged ions. The deceleration starts in the ESR accompanied by stochastic and electron cooling. The beam is stored at 400 MeV/nucleon, cooled stochastically, decelerated to 30 MeV/nucleon, cooled by electrons, decelerated to 4 MeV/nucleon, again electron cooled, and ejected after rebunching. Then the ions are injected into a linear decelerator to be bunched and decelerated first to 500 keV/nucleon and finally to 6 keV/nucleon. For final cooling to an energy equivalent of 4 K the ions are caught in flight in a Penning trap. There the highly charged ions are cooled with electrons and resistively before ejection to the experiments. In a number of commissioning beam times, the deceleration in the ESR, the extraction, bunching and deceleration to 0.5 MeV/u, and finally 6 keV/u, has been shown. The remaining steps, capture and cooling in a cryogenic Penning trap are ongoing and will also be discussed.