A new design of truly selfshielding baby-cyclotrons for positron emitter production

The successful design of the Cyclone 30, a 30-MeV H/sup -/ cyclotron, gave birth to an original design of truly selfshielding baby-cyclotrons dedicated to positron emitter production. This new negative ion cyclotron will deliver 10-MeV protons and 5-MeV deuterons. Up to eight targets are located inside the circular return yoke of the magnet, which serves as a primary neutron and gamma-ray shield. The cyclotron is embedded in an additional neutron shield made of borated-hydrogenated material. One of the main goals of the design is the ease of access to the targets and to the cyclotron inner parts without compromising the shielding efficiency. Any combination of two opposed targets can be irradiated simultaneously. The size and weight of the proposed system are considerably reduced compared to those of existing cyclotrons. >