STATUS OF THE SUPERCONDUCTING RING CYCLOTRON AT RIKEN RI BEAM FACTORY

A superconducting ring cyclotron (SRC) was success-fully commissioned to work as the final energy booster of the RI beam factory (RIBF) in RIKEN. SRC is the world’s first ring cyclotron that uses superconducting mag-nets, and has the strongest beam bending force among the cyclotrons. It can boost the ion beam energy up to 440 MeV/nucleon for light ions and 350 MeV/nucleon for very heavy ions such as uranium nuclei to produce intense radioactive beams. The ring cyclotron consists of 6 major superconducting sector magnets with a maximum field of 3.8 T. The total stored energy is 235 MJ, and its overall sizes are 19 m diameter, 8 m height and 8,300 tons. The magnet system assembly was completed in August 2005, and successfully reached the maximum field in November 2005. After magnetic field measurements for two months, the other hardware than the superconducting magnets was installed. The first beam was extracted from SRC on 12/28/2006. From May 2007 we started to supply uranium beams to nuclear scientist to produce RI beams