Optimization of Electron Beams Based on Plasma-Density Modulation in a Laser-Driven Wakefield Accelerator
Lintong Ke, Changhai Yu, Ke Feng, Zhiyong Qin, Kangnan Jiang, Hao Wang, Shixia Luan, Xiaojun Yang, Yi Xu, Yuxin Leng, Wentao Wang, Jiansheng Liu, Ruxin Li
Abstract
We demonstrate a simple but efficient way to optimize and improve the properties of laser-wakefield-accelerated electron beams (e beams) based on a controllable shock-induced density down-ramp injection that is achieved with an inserted tunable shock wave. The e beams are tunable from 400 to 800 MeV with charge ranges from 5 to 180 pC. e beams with high reproducibility (of ~95% in consecutive 100 shots) were produced in elaborate experiments with an average root- mean-square energy spread of 0.9% and an average divergence of 0.3 mrad. Three-dimensional particle-in-cell (PIC) simulations were also performed to accordingly verify and uncover the process of the injection and the acceleration. These tunable e beams will facilitate practical applications for advanced accelerator beam sources.