COOLER SYNCHROTRON COSY

COSY Julich is a cooler synchrotron and storage ring delivering high p recision beams with at present up to 5.10(10) protons with momenta bet ween 600 MeV/c and 3.3 GeV/c for medium energy physics. Two cooling sy stems are used to accomplish this goal. An electron-cooling system tha t reaches up to a momentum of 645 MeV/c and a stochastic cooling syste m that covers the upper momentum range from 1500 to 3300 MeV/c. Since its inauguration in April 1993 substantial progress in developing beam s for internal and external experiments has been achieved and the phys ics program is now running. At the beginning of 1996 a polarized proto n beam could be successfully accelerated up to 820 MeV/c for the first time.