SIS - an accelerator facility for relativistic heavy ions

At GSI a new facility for the acceleration of heavy ions to relativistic energies was designed. A large synchrotron dubbed SIS will provide high current heavy ion beams in the extremely broad energy range from 20 MeV/u up to 14 GeV/u. The UNILAC - a 10 MeV/u linear accelerator now in use for atomic and nuclear physics - will serve with a few pulses per second as injector machine for the synchrotron. In order to boost beam intensities up to 2 mA by acceleration of singly or doubly charged ions a small new injector linear accelerator will be installed in front of the UNILAC. In a review of relativistic heavy ion accelerators the SIS will be compared to other concepts. Relevant design features such as charge exchange processes and vacuum requirements are discussed. (Auth.)