Conceptual Design of Scanning Magnets for Superconducting Proton Therapy Facility

The performance of scanning magnets is the key to the treatment of proton accelerator in nozzle of the Superconducting Proton Therapy System (SPTS), which directly affects the quality of the proton beam and the size of the radiation field. The scanning magnets set at the entrance of the beam irradiation system are two dipole magnets to scan the beam in both horizontal and vertical directions and form the irradiation field to be tumor shape. In this paper, the theoretical calculation and software simulation have carried out to design scanning magnets for the SPTS in brief. The distribution of magnetic field is improved by structure optimization of scanning magnet and comparative analysis of magnetic induction intensity distribution curve in medium plane. The optimum structures of scanning magnets are got, which can meet the beam integral field uniformity and improve scanning accuracy. The study provides the key technical support to proton therapy of the SPTS.