Energy spread minimization in a cascaded laser wakefield accelerator via velocity bunching
Energy spread minimization in a cascaded laser wakefield accelerator via velocity bunching
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通过速度聚束最小化级联激光尾场加速器中的能量扩散
DOI：
10.1063/1.4947536
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发表时间：
2016
影响因子：
2.2
通讯作者：
Xu Zhizhan
中科院分区：
文献类型：
--
作者：
Zhang Zhijun;Li Wentao;Liu Jiansheng;Wang Wentao;Yu Changhai;Tian Ye;Nakajima Kazuhisa;Deng Aihua;Qi Rong;Wang Cheng;Qin Zhiyong;Fang Ming;Liu Jiaqi;Xia Changquan;Li Ruxin;Xu Zhizhan
我们提出了一种方案，通过在级联激光尾迹加速器中插入一个阶段来压缩电子束的纵向空间分布，从而将电子束(电子束)的能量扩散最小化到千分之一级。在该方案中，设计了三段等离子体级，分别用于电子注入、电子束长度压缩和电子束加速。注入阶段被捕获的电子束转移到压缩阶段一个尾场周期中心的零位相区，由于速度聚束，电子束的长度可以大大缩短。在进入第三级加速后，由于电子束长度缩短，在其能量啁啾得到补偿之前，电子束可以被加速到更高的能量。一维理论和二维粒子模拟表明，该方案可以在不损失电荷的情况下，产生具有0.2%均方根能量分布和低横向发射度的电子束。
We propose a scheme to minimize the energy spread of an electron beam (e-beam) in a cascaded laser wakefield accelerator to the one-thousandth-level by inserting a stage to compress its longitudinal spatial distribution. In this scheme, three-segment plasma stages are designed for electron injection, e-beam length compression, and e-beam acceleration, respectively. The trapped e-beam in the injection stage is transferred to the zero-phase region at the center of one wakefield period in the compression stage where the length of the e-beam can be greatly shortened owing to the velocity bunching. After being seeded into the third stage for acceleration, the e-beam can be accelerated to a much higher energy before its energy chirp is compensated owing to the shortened e-beam length. A one-dimensional theory and two-dimensional particle-in-cell simulations have demonstrated this scheme and an e-beam with 0.2% rms energy spread and low transverse emittance could be generated without loss of charge.