线极化波对带电粒子的加速机制  

Charged particles acceleration by linearly polarized electromagnetic wave in medium with tapered refractive index

作　　者：王志国 周小文 刘超超[1] 许琛 贾立颖 王倩[1,2] 黄可淼 赵欣 刘荣明 李炳山[1,2] Wang Zhiguo;Zhou Xiaowen;Liu Chaochao;Xu Chen;Jia Liying;Wang Qian;Huang Kemiao;Zhao Xin;Liu Rongming;Li Bingshan(National Engineering Research Center for Magnetic Materials,Beijing 102600,China;BGRIMM Magnetic Materials&Technology(Fuyang)Co Ltd,Fuyang 236000,China)

机构地区：[1]国家磁性材料工程技术研究中心,北京102600 [2]北矿磁材(阜阳)有限公司,安徽阜阳236000

出　　处：《强激光与粒子束》2019年第1期41-45,共5页High Power Laser and Particle Beams

基　　金：北京矿冶科技集团青年基金项目(QCJ201829);国家自然科学基金项目(11575015)

摘　　要：讨论了线极化波对带电粒子三种加速机制:(1)介质折射率递减但外加磁场保持不变;(2)介质折射率不变但外加磁场递增;(3)介质折射率递减且外加磁场递增。结果显示,在一定的加速距离内,按照机制(3)利用LPEMW加速电子的效率最高。另外,机制(3)可以避免机制(2)中电子在加速过程中回飞的问题,这一点在利用线极化波(LPEMW)加速电子束或带电粒子束时非常重要。Acceleration of electrons or charged particles by a linearly polarized electromagnetic wave(LPEMW)propagating in a medium along an external magnetic field is theoretically studied.We have investigated three acceleration cases here:(Ⅰ)the medium’s refractive index changes with location but the external magnetic field is constant,(Ⅱ)the medium’s refractive index is constant but the external magnetic field increases with the distance in the wave propagation direction,and(Ⅲ)both the medium’s refractive index and the external magnetic field change with the distance.The results show that the most efficient(i.e.,at a fixed acceleration distance,obtaining the highest relativistic factor)electron acceleration by the LPEMW can be fulfilled in case(Ⅲ).Besides,in case(Ⅲ),the drawback(such as charged particles’going backward for a while)in the acceleration of case(Ⅱ)can be avoided or greatly reduced,which is very important for acceleration of a bunch of electrons or charged particles by LPEMW.It is believed that the acceleration mechanism found in case(Ⅲ)can be helpful in the design of a compact and efficient chargedparticle accelerator.

关 键 词：带电粒子加速器 变化折射率 外磁场 线极化电磁波 

分 类 号：O411.4[理学—理论物理]