强激光与粒子束, 2015, 27 (7): 072003, 网络出版: 2015-07-10
强激光与柱腔靶作用下准直高能电子束的产生
High-energy collimated electron acceleration from ultra-intense laser interaction with tube targets
超强激光 柱腔靶 PIC模拟 准直超热电子 准静态磁场 表面电子加速 ultra-intense laser tube target PIC simulation collimated fast electrons quasistatic magnetic field surface electron acceleration
摘要
利用二维PIC粒子模拟程序研究了超短超强激光脉冲与柱腔靶相互作用产生的表面超热电子加速现象.采用光强为1021 W/cm2量级的超高斯激光脉冲掠入射进入柱腔靶,在靶的内壁上观察到了GeV量级的表面超热电子.超热电子束被准静态的电场和磁场约束在内壁表面附近,保证了电子束的准直性,发散角仅为1.6°;并且由于超热电子束在纵向激光电场中加速了mm级的距离,激光到高能电子(>100 MeV)的转换效率达到了26.6%.另外,通过多参数模拟和理论解析讨论了激光的光强以及横向空间分布对这种表面超热电子加速的影响.
Abstract
Two-dimensional PIC(particle-in-cell) simulation is used to investigate the interaction between ultra-intense short-pulse lasers with tube targets.When an ultra-intense super-Gaussian laser pulse propagates at a grazing incidence angle into the tube target,GeV-class electron acceleration is observed on the inner surface.Fast electrons are confined along the surface by quasistatic electric and magnetic fields,resulting in a small divergence angle of the generated electron beam.These surface fast electrons can be accelerated for a long distance along the tube;as a result,the energy conversion efficiency is very high.The influence of the laser intensity and the transverse profile on the surface electron acceleration process is also discussed in the article.
何武, 周维民, 张智猛, 矫金龙, 单连强, 蒋刚. 强激光与柱腔靶作用下准直高能电子束的产生[J]. 强激光与粒子束, 2015, 27(7): 072003. He Wu, Zhou Weimin, Zhang Zhimeng, Jiao Jinlong, Shan Lianqiang, Jiang Gang. High-energy collimated electron acceleration from ultra-intense laser interaction with tube targets[J]. High Power Laser and Particle Beams, 2015, 27(7): 072003.