Design of a Shuttle Microtron for Radiation Therapy

A design proposal for a new type of electron accelerator for radiotherapy applications is presented. The three-pass, fixed-magnet shuttle microtron is designed to allow continuous variation of electron beam energy from 4 to 24 MeV, while providing maximum current levels for x-ray treatment at 6, 12, and 20 MeV. The reflector magnets are structured for both axial and radial beam focusing and the entire accelerator fits into the horizontal arm of a rotatable therapy gantry.