Radiation shielding of a beta-beam rapid cycling synchrotron

In a future beta-beam facility, radioactive ions (namely, 6He and 18Ne) are produced, accelerated, and then stored in a large decay ring, where they eventually produce neutrino beams through beta decay. Radiation protection is of great concern for this facility because decay products are present at all energies along the accelerator chain. Experimental data on radioactivity produced by ion accelerators are still poor, and few Monte Carlo codes can transport ions. All present calculations are performed with the Monte Carlo code FLUKA. The radiation environment generated by ion beam losses is compared with the available experimental data. The attenuation length of radiation in concrete is calculatedfor 6 He and18Ne at four different energies, from 100 to 1650 MeV/u. A preliminary shielding design for the Rapid Cycling Synchrotron, purpose-designed for a beta-beam accelerator chain at CERN, is proposed.