Beam quality improvement of ionization injected electrons by using chirped pulse in wakefield acceleration
Beam quality improvement of ionization injected electrons by using chirped pulse in wakefield acceleration
复制标题
在尾场加速中使用啁啾脉冲改善电离注入电子的束流质量
DOI：
10.1088/1361-6587/ab249e
复制
发表时间：
2019
影响因子：
2.2
通讯作者：
Shao Fu-Qiu
中科院分区：
文献类型：
--
作者：
Cui Ye;Zhang Guo-Bo;Ma Yan-Yun;Zou De-Bin;Yang Xiao-Hu;Chen Min;Liu Jian-Xun;Ge Zhe-Yi;Tian Li-Chao;Gan Long-Fei;Shao Fu-Qiu
采用粒子模拟方法研究了啁啾激光脉冲驱动的韦克菲尔德加速中电离诱导电子注入的过程。研究发现，负（正）啁啾对激光脉冲有纵向拉伸（压缩）作用，且韦克菲尔德振幅与啁啾符号无关。另一方面，正啁啾脉冲的快速压缩导致韦克菲尔德势差的减小，从而打破了电离注入条件，导致注入截断。有效注入仅持续几百微米，具体注入长度由啁啾参数决定。结果表明，该方案可以稳定地产生一束高调谐准单能电子束，其能散窄，中心能量可达数百MeV，电荷量可达数十pC。
Ionization-induced electron injection in a chirped laser pulse driven wakefield acceleration is investigated through particle-in-cell simulations. We find that negative (positive) chirp can longitudinally stretch (compress) laser pulse, and the wakefield amplitude can be enhanced regardless of the chirp sign. On the other hand, the rapid compression of a positively chirped pulse leads to the decrease of the wakefield potential difference, which breaks the ionization injection condition and consequent injection truncation occurs. The effective injection only lasts for a few hundred micrometers and the detailed injection length is determined by the chirp parameter. As a result, a highly tunable quasi-monoenergetic electron beam with narrow energy spread, hundreds of MeV central energy and tens of pC charge can be stably produced by this scheme.