第33卷
第1期
2013年
3月
核科学与工程
Nuclear Science and Engineering
Vol.33No.1
Mar.2013
重离子同步加速器中剥离累积时
碳膜对束流的影响研究柴伟平1.2，夏佳文1，杨建成1，石健1,2
(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）
摘要：治癌专用重离子加速器HITFiL中同步加速器的注人系统采用了剥离注人方式。剩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，但粒子多次穿越利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面导致束流损失；2)刹高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高导致束流中心动量减少并使得动量分散增长，本文通过研究剩离注人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。
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
中图分类号：TL503.3
文章标患码：A
文章编号：0258-0918(2013)01-0039-06
Theeffectsof carbonfoil onbeamsin stripping-accumulation
of a heavy-ion synchrotron
CHAI Wei-pingi-, XIA Jia-wen', YANG Jian-cheng', SHI-Jian'-2
(1. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou of Gansu Prov. 730000, China;
2. Graduate University of Chinese Academy of Sciences, Bejing 100049, Chins)
Abstract: 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 of
收稿日期：2012-09-20；修图日期：2012-12-04
基金项目：国家重点基础研究发展计划(2010CB834204)
作者简介：柴伟平（1984一），男，甘策永昌人，博士研究生，加速器物理专业 38