The Superconducting Ring Cyclotron in RIKEN

RIKEN Nishina Center for accelerator-based science in RIKEN is constructing the radioactive isotope beam factory (RIBF), which is capable of providing the world´s most intense RI beams over the whole range of atomic masses. The world´s first superconducting ring cyclotron (SRC) is the final booster in the RIBF accelerator complex which is able to accelerate all-element heavy ions to a speed of about 70% of the velocity of light. Assembling of six superconducting sector magnets in the SRC vault was completed in August 2005. This paper describes results of their cool-down and excitation tests, which were performed to check the magnet system from the various points of views: magnetic force, coil protection, magnetic field and operation of their cryogenic cooling system.