Design Aspects and Operation Experience With a Novel Superconducting Cyclotron for Cancer Treatment

Two superconducting cyclotrons have been delivered by ACCEL to produce 250 MeV protons for cancer treatment. Based on a conceptual design of the national superconducting cyclotron laboratory (NSCL) these machines are the first ones of their kind being engineered and built by industry. Application of superconductivity provides better and more reliable beam performance as compared to normal conducting cyclotrons. We present the assessment for applying superconductivity, review the design and assembly, and report on the first year of operation experience with regard to cryogenic and magnetic performance.