Lattice Design of Dedicated Synchrotron for Proton Therapy

Abstract

A compact model of synchrotron accelerator facility is proposed for the treatment of deep seated tumors with proton therapy. The extracted beam from the existing C-30 cyclotron is first injected into the model of synchrotron. The injected beam is specified with its longitudinal plane as well as its horizontal and vertical emittances. For this design to be compatible with the cyclotron C-30 the synchrotron should be kept compact and the number of magnet components must be low. The modeled synchrotron layout is designed using the computer codes MADX and AGILE in order to accelerate the injection proton ions from 30 MeV to a maximum extraction energy of 250 MeV with magnetic rigidity of 2.433 Tm. In this lattice arrangement with phase advance of about 90 degrees in two horizontal and vertical planes doublet cells are utilized. This ring consists of two long straight sections for RF and injection/extraction equipment, as well as four short straight sections. For chromaticity correction two families of sextupoles are used. To prohibit emittance growth, a matching at injection in longitudinal plane was performed. The proton beam energy spread of 2% can be improved to 0.1% at injection by using the designed achromatic system. For the proton beam acceleration a RF cavity with an approximate voltage of 160 volts with a frequency in the range of 2.3 up to 14 MHz is used.