Magnetic Field Design of Coil-Dominated Magnets Wound With Coated Conductors

Coil-dominated magnets wound with coated conductors were designed for an FFAG accelerator for carbon therapy, which was designed by applying linear approximation. When designing the coil-end of the magnets, we applied differential geometry. To apply the differential geometry to three-dimensional windings with coated conductors, we introduced the concept of generalized flat-wise bending. Thereby, the combination of flat-wise bending and torsion was considered as bending of developable surface. Generated magnetic field was calculated, and the positions of conductors were optimized to minimize the field error. Three dimensional shapes of magnets were successfully designed with constraints on generalized flat-wise bending and edge-wise bending of coated conductors.