COMPACT PROTON AND CARBON ION SYNCHROTRONS FOR RADIATION THERAPY

A compact proton and carbon ion synchrotron development program is approved in 2001 to promote the advanced radiation treatment by developing a suitable medical accelerator adopting new technologies. They depend on the high magnetic field to make the ring as small as possible. The maximum proton (carbon ion) energy is 200 MeV (300 MeV/u) with the circumference of 12 m (16m) at the maximum dipole field of 3 T (4 T). Main concerns of this manuscript are the development of a high field magnet with a uniform field distribution and a short high voltage broadband RF cavity. Three dimensional transient field calculations were carried out under the pulse excitation with the rise time of 5 ms and the beam behaviours are also simulated under the sextupole error field in the dipoles. Beam optics and transverse beam stability studies are presented including the lattice design.