利用尾场结构实现速度压缩中的非线性补偿  

Nonlinear compensation in velocity realized by wakefield structure

作　　者：李志垚 陈寒 杜应超[1] LI Zhiyao;CHEN Han;DU Yingchao(Department of Engineering Physics,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学工程物理系,北京100084

出　　处：《核技术》2018年第8期21-26,共6页Nuclear Techniques

基　　金：国家自然科学基金(No.11375097)资助~~

摘　　要：在高亮度电子束装置中,限制速度压缩方法应用的一个主要原因是压缩过程中非线性效应导致的非均匀压缩。为补偿速度压缩过程中的非线性效应,避免出现非均匀压缩导致的局部高流强和束团品质下降,提出了基于尾场结构的非线性补偿方法。该方法利用束流在尾场结构中产生的电场来实现对束流纵向相空间的调制,从而对速度压缩过程中的非线性效应进行补偿,获得均匀压缩的高品质束流。利用ASTRA模拟程序对该过程进行了详细模拟,结果表明:利用该方法可以获得均匀压缩的、发射度增长可控的高品质束流。同时,经均匀压缩后束流切片能散从约3 keV提升到了20 keV左右,有利于抑制在后续压缩过程中的微束团不稳定性。[Background] An important limitation for using of velocity bunching is nonlinear effect which leads to non-uniform compression and beam quality deterioration. [Purpose] This study aims to realize nonlinear compensation caused by nonlinear effect in velocity bunching. [Method] Based on the self-induced wakefield while the beam passing through a wakefield structure, nonlinear compensation is achieved by modulation of beam longitudinal phase space. Start-to-end simulation by ASTRA is performed in this paper. [Results] The results show that slice energy spread of beam increased from about 3 keV to about 20 keV which is benefit to suppress the micro-bunching instability in subsequent process. [Conclusion] Uniform velocity bunching can be realized by the method of nonlinear compensation to general high quality uniformly compressed beam.

关 键 词：速度压缩 尾场结构 非线性补偿 

分 类 号：TL99[核科学技术—核技术及应用]