Research on frequency modulation technology and its verifications of superconducting synchrocyclotron for cancer therapy

Superconducting synchrocyclotron for proton therapy has grown rapidly in recent years. Frequency modulation is considered as the unique technology of synchrocyclotron. In the process of theoretical cavity design of CIAE-230 MeV superconducting synchrocyclotron, the frequency modulation algorithm, based on the characteristic of cavity electromagnetic field distribution, is developed and then validated on the model cavity test. The rotor system works effectively at the speed of 7500 RPM, which indicates that the cavity modulation frequency reaches the kHz level. The interactive design related to the magnetic field is also introduced in this paper. The technical feasibility research on frequency modulation in this paper paves the way for the whole machine development.