DESIGN AND CONSTRUCTION OF A SUPERCONDUCTING MAGNET SYSTEM FOR AN ELECTRON-CYCLOTRON-RESONANCE (ECR) ION-SOURCE

The cyclotron accelerator at Laboratorio Nazionale del Sud in Catania, Italy will be equipped with a high-performance ECR ion source. This s ource which is presently under construction comprises a so-called Mini mum-B magnetic bottle of 130 mm diameter and 480 mm length. The specif ied magnetic field values are 2.7 T, 1.6 T and 0.37 T respectively for the axial component at the two ends and at the center. The transverse field component is required to reach 1.4 T at the cylindrical boundar y. The complex field configuration is produced by means of a compound superconducting coil system whose essential parts are an approximately 800 mm long sextupole and three coaxial solenoids surrounding the sex tupole. All windings will be made from NbTi composite conductors and i mpregnated with epoxy resins. Bath cooling at 4.5 K for all coils will be provided by a warm-bore type cryostat with horizontal axis. The pa per presents design and construction of the coil system, its support s tructure and the cryostat.