The Scanning Magnets for Proton Therapy Designed by SINAP

A new proton therapy scanning system for the treatment of cancer has been accomplished at the Shanghai Institute of Applied Physics (China). It is mainly comprised of two separate dipole magnets, which have been fabricated and now are under commission. According to the design requirements, we have confirmed the dimensions of the magnets and optimized the local and integrated field quality. The static electromagnetic field analysis has been completed in OPERA 3D, including the spatial distribution and interference of the magnetic fields, the optimization of the pole, the verification of the scanning scope. The dynamic behaviors of the two dipole magnets were analyzed respectively and approaches to reduce the effects of the eddy currents were integrated into the design. In addition, the static and dynamic magnetic field measurements were finished. Compared with the simulated magnetic fields, the measurement results indicate that the design of the scanning magnets reaches the design targets. All the specific design results of the scanning magnets are concluded in this paper.