HITFiL同步加速器剥离注入

摘要

一台新的治癌专用加速器HITFiL正在设计和建造中,其中一台同步加速器为其主加速器,以高紧凑性、高可靠性和低成本为设计目标.同步加速器的注入系统采用剥离注入方式,剥离注入与单圈注入方式相比能达到较高的注入效率,而其造价明显低于多圈注入加电子冷却的注入方式.治癌采用碳粒子束,从ECR离子源产生的C5+离子经过回旋加速器预加速后在同步加速器注入点处剥离成为C6+注入到环里.详细阐述了该注入系统的设计方案,并对整个注入过程进行了计算机模拟.在模拟过程中,对束流的注入效率、束流损失机制和粒子数增益进行了研究,得到了实空间和相空间的粒子分布和发射度增长趋势,得到了满足要求的束流流强.%A new accelerator dedicated to hadron therapy,the Heavy-Ion Therapy Facility in Lanzhou (HITFiL),is under construction.As the main accelerator of HITFiL,a heavy-ion synchrotron is designed with special attention paid to compact structure,high reliability and low cost.Stripping injection scheme is adopted for the synchrotron,which is more efficient than single-turn injection and less costly than multi-turn injection supported by electron-cooling.Carbon beams are adopted for HITFiL cancer therapy:Cs+ ions from an electron cyclotron resonance ion source,are pre-accelerated by a cyclotron,stripped into C6+ ions by a carbon foil located in a main dipole of the ring and injected into the central orbit of the ring at the same time.The detailed injection scheme for the synchrotron is presented,and the stripping injection process is simulated.The injection efficiency,complete beam loss factors and the particle number gain are investigated.In addition,beam properties including beam distribution in real and phase space and emittance growth due to foil traversal are studied,and the required beam intensity is achieved.