Study of charge exchange injection in HITFiL

A new accelerator complex dedicated to hadron cancer therapy, Heavy-Ion Therapy Facility in Lanzhou (HITFiL), is proposed and designed. Based on the operating experience and existing technology on HIRFLCSR, a heavy-ion cyclotron is used as an injector instead of a linac. A heavy-ion synchrotron as main component is designed with special attention paid to compact structure, high reliability and low cost. HITFiL is designed to accommodate both proton and carbon-ion using the same injecting channel but different injecting points. Charge exchange injection scheme, which is more efficient compared with single-turn injection but less costly compared with multiple multi-turn injection aided by electron-cooling, is adopted. H2 + or C5+ beams, preaccelerated by the cyclotron, are stripped into H + or C6+ by a carbon foil at injection point, then injected and merged into synchrotron central orbit. The design of the injection system is presented in this paper. The whole injection process is simulated, optimization of parameters on injecting efficiency, painting scheme and emittance growth are performed. The resulting beam distribution in phase space after injection is achieved. Copyright © 2011 by IPAC'11/EPS-AG.