重离子同步加速器中剥离累积时碳膜对束流的影响研究  

The effects of carbon foil on beams in stripping-accumulation of a heavy-ion synchrotron

作　　者：柴伟平[1,2] 夏佳文[1] 杨建成[1] 石健[1,2] 

机构地区：[1]中国科学院近代物理研究所,甘肃兰州730000 [2]中国科学院大学,北京100049

出　　处：《核科学与工程》2013年第1期38-43,共6页Nuclear Science and Engineering

基　　金：国家重点基础研究发展计划(2010CB834204)

摘　　要：治癌专用重离子加速器HITFiL中同步加速器的注入系统采用了剥离注入方式。剥离膜的存在使束流克服了刘维定理的限制从而累积达到较高流强,但粒子多次穿越剥离膜也会造成束流损失并使得束流品质变坏,其中包括:1)粒子从膜原子中俘获电子使粒子电荷态发生改变而导致束流损失;2)剥离膜对束流的多重库仑散射导致束流发射度增长;3)束流在剥离膜中的能损及能量岐离导致束流中心动量减少并使得动量分散增长。本文通过研究剥离注入过程中粒子与物质的相互作用规律,用蒙特卡罗方法建立了剥离膜与粒子的作用模型,在对ACCSIM程序改进的基础上研究了剥离膜对束流的影响。Stripping-injection scheme is adopted in the synchrotron of an accelerator complex named as HITFiL. HITFIL is dedicated to cancer therapy. High intensity can be reached by using the stripping-injection as the limit of Liouville＇s theorem is broken due to charge-exchange. But unavoidable traversals of the circulating beams through the foil may cause beam-losses and deteriorations of beam quality, including. 1） beam-losses caused by an alteration of the particles＇ charge state; 2） emittance growth caused by Multiple Coulomb Scattering; and 3） decrease of mean-momentum and growth of momentum spread induced by energy loss and energy loss straggling. In this paper, the model of particle-foil interaction is established by Monte Carlo processes. The effects ofthe stripping foil on beams are studied based on an improvement of the ACCSIM code.

关 键 词：剥离累积 ACCSIM 发射度增长 动量分散增长 蒙特卡罗模拟 

分 类 号：TL503.3[核科学技术—核技术及应用]