摘要
在以时间为自变量的PARMTEQ程序的基础上 ,添加了另一带相反电荷的束流进行动力学计算 ,同时考虑了正、负离子束加速的空间电荷效应和束团间的作用 .并针对特定结构参数的RFQ加速器 ,给出了双束加速的动力学模拟过程和结果 .模拟计算的目的在于研究正、负离子束在RFQ加速结构中同时加速所引起的动力学问题 .结果表明 ,正、负离子束同时加速有助于克服径向空间电荷效应 ,但在流强较大时 ,双束加速时 ,将会在纵向出现明显的异性电荷之间的“捕捉”(trap)现象 ,从而导致纵向粒子损失数目的增加 .因此 ,为实现双束加速 ,必须专门重新设计RFQ加速器 ,使其传输效率高于单束 。
An additional beam with opposite charge state is added into the dynamic simulation of the t-Code program PARMTEQ. The space charge effect and multi-bunch effect during the positive and negative ion beams acceleration are considered. The result is given for a four-vane type RFQ accelerator. The purpose of simulation is focused on the investigation of possible dynamic problems caused by two-beam acceleration in RFQ structure. Two-beam acceleration is prior to diminish the transverse space charge effect, but “trap” between opposite charge state ions in longitudinal position appears when the beam current is large, which is the main cause of the increasing number of longitudinal loss. Therefore new RFQ structures should be designed specially for two-beam acceleration to obtain higher transmission rate than single beam acceleration.
出处
《高能物理与核物理》
CSCD
北大核心
2004年第6期659-663,共5页
High Energy Physics and Nuclear Physics
基金
国家重点基础研究规划项目 (G19990 2 2 60 0 )资助~~
