基于高重频激光尾波场加速的高品质稳定电子束产生

近年来，激光尾波场加速得到了长足的进步与发展，其产生的电子束天然具有脉宽短（飞秒级）、尺寸小（微米级）以及与驱动激光同步精度高等优点，在泵浦探测、超快电子衍射和新型辐射源产生等方面具有广阔的应用前景。然而，受限于驱动激光的低重复频率和激光等离子体相互作用不稳定性等因素，目前激光尾波场加速的电子束在重复频率、稳定性和品质上还未能很好地满足实际应用的需求。本项目拟采用理论与实验相结合的方法，探索高重频激光尾波场加速产生高品质稳定电子束的新方案。通过操控激光参数和等离子体密度控制电子束的注入过程、加速相位和能量啁啾演化，实现其发射度的减小与能散度的压缩；并结合飞秒探针技术和自适应光学技术进行密度的诊断与激光参数的自反馈控制，提高电子束的稳定性，从而产生具有高重复频率的高品质稳定电子束源。本项目的研究将为高重频、高品质稳定电子束的产生提供一个有效的解决方案，为激光尾波场加速器的进一步发展做出贡献。

In recent years, a great progress has been made on laser wakefield accelerators (LWFAs), the generated electron beam naturally has the characteristics of femtosecond pulse width, micrometer size and high-resolution synchronization with the driving laser, which thus has a wide range of application prospects in pump-probe detection, ultra-fast electron diffraction and novel radiation sources. However, due to the low repetition of the driving laser pulse and the instability of the laser-plasma interaction, the electron beam from the LWFA has not been able to meet the application requirements well in terms of its stability (shot to shot stability), repetition-rate and beam-quality. Therefore, this project intends to explore the novel routes of high rep-rate laser driven based plasma wakefield to produce high-quality stable electron beams with high rep-rate by combining theoretical and experimental methods. By controlling the laser parameters and the plasma density distribution, the injection process, acceleration phase and energy chirp evolution of electron beams are controlled, and the transverse emittance and energy spread are reduced. Combining femtosecond probe technology and adaptive optics, plasma density diagnosis and the active feedback control of laser parameters are realized to improve the stability of electron beams. So that stable electron beam sources with high rep-rate and high-quality can be obtained. It’s anticipated that the research of this project will provide an effective solution for the generation of high rep-rate and high-quality stable electron beams, contributing to the further development for the LWFA.