Storage rings for fast cooling of antiproton and radioactive ion beams

Production, fast cooling, and accumulation of intense secondary beams, antiprotons and rare isotopes, are key issues of the new accelerator facility proposed for GSI. Single primary bunches of 2x10¹³ protons at 29 GeV and 1x10¹² U²⁸⁺-ions at 1 GeV/u shall be delivered from the new, fast-ramped 100 Tm-synchrotron SIS100. A large acceptance, reversible polarity collector ring CR is foreseen for fast RF debunching followed by fast stochastic pre-cooling in all phase planes. The envisaged total precooling times are 4-5 s for 3 GeV antiprotons and 0.5-1 s for fully stripped RI at 740 MeV/u. Stochastic accumulation of antiprotons shall be made in a separate accumulator ring RESR. The RI beams are transferred to a New Experimental Storage Ring NESR, where electron cooling (EC) is applied simultaneously to internal target experiments. For experiments with antiprotons, a special 50 Tm storage ring HESR shall be equipped with internal target and EC up to 15 GeV, optionally also with stochastic cooling. The HESR design aims at a maximum luminosity of 2x10³²cm^-2s^-1 and at 100 keV energy resolution at lower luminosity. Basic design issues for the storage ring complex and results of numerical simulations of cooling rates and equilibrium beam properties are discussed.