MAGNET SECTOR DESIGN FOR A 15-GeV SUPERCONDUCTING CYCLOTRON

Pole shape designs are presented which maintain focused and isochronous orbits in the two stages of a super-conducting ring cyclotron kaon factory (CANUCK). The first stage of 15 sectors takes a 100 UA proton beam extracted from TRIUHF to 3.5 GeV. The second stage of 42 sectors continues the acceleration to 15 GeV. The orbit properties have been determined using a median plane magnetic field computed from the current distri-bution in the coils and in current sheets simulating the saturated steel. The design process and the effects of various factors, including softness of the edges, cross-section of the coils and negative field gullies, will be described