The Pulsed Magnet and Power Supply System for 50–250 MEV Electron Radiotherapy

Very high-energy electron (VHEE) beams in the range 50–250 MeV for treatment of deep-seated tumors have been studied to evaluate the feasibility for radiotherapy. In comparison with various existing radiotherapies, VHEE therapy is most likely to develop an extremely rapid treatment in order to overcome the effect of physiology motions such as breathing, organ filling, and peristalsis. In this report, we propose an efficient method to steer the electron beam by using a window frame fast kicker magnet which can deflect the electrons both in vertical and horizontal directions. The steering capability is achieved by installing two pairs of individual coils for the fast kicker. Two separate pulsed power supplies are equipped for the kicker magnet. In order to facilitate the VHEE therapy, the bending angle of the magnet capability is designed to reach 6.4° and the magnet dimension is 50 cm in length and 6 cm in height. The required pulsed magnetic field and the corresponding pulsed current are 0.2 T and 8 kA, respectively.