迈克尔逊干涉仪型光路用于高猝发重复频率高束团电荷量电子束团序列的产生研究

Photoinjector has been developed very fast as electron sources to provide electron pulse with high brightness since 1980s. It has been applied in different kinds of research facilities such as synchrotron radiation light source., free electron laser(FEL), electron-positron collider, energy recovery linac, ultra-fast electron diffraction and Compton scattering X-ray and etc. Technique of drive laser including amplification, harmonic wavelength conversion, RF and laser synchronization and pulse shaping has also developed. Including constructed and under-construction and awaiting construction FEL facilities, the drive laser systems focus on both low repetition frequency with high peak current and high repetition frequency with low peak current. High repetition frequency is the way FEL going which would play a bigger role in life sciences, information technology, photo-chemical, nano-materials and other fields, and challenge the high brightness electron sources. For the high burst mode FEL type drive laser sysetem, high requirements are put on repetition frequency and pulse energy, but I have not seen any report on this kind of drive laser system. The electron beam experiments with high burst repetition frequency will be carried out.

光阴极注入器作为一种可以提供高亮度脉冲电子束的电子源得到了快速发展，广泛应用于同步辐射、自由电子激光、正负电子对撞机、能量回收直线加速器、超快电子衍射和逆康普顿散射X射线源等基于加速器的研究装置。而作为光阴极注入器的最重要部分之一，驱动激光系统也得到了不断发展，放大、倍频、同步和脉冲整形等技术的水平不断提高。目前包括在运行以及在建的基于光阴极注入器的加速器装置，其驱动激光系统主要集中于低重复频率高峰值流强和高重复频率低峰值流强两类。高重频是自由电子激光的发展方向，具有越来越高的平均功率，能在生命科学、信息技术、光化学、和纳米材料等多个学科发挥更大的作用，同时这也对高平均功率高亮度电子源提出了巨大的挑战。对于用于高猝发重频自由电子激光的驱动激光系统，对重复频率和脉冲能量同时提出了高要求，但是目前还未曾有报道此类驱动激光系统。本项目将开展高猝发重复频率高峰值流强电子束形成的实验研究

本项目基于薄膜偏振分束镜，完成了将266nm线偏振激光的4脉冲分束、合束、脉冲间隔操控等一系列实验研究工作。研究显示利用偏振分光元件可以很好的将激光分成2个脉冲，并且分束之后的激光易于合束。分光之后，4个激光脉冲能量一致性可以达到3%以内，指向一致性可以小于10 urad。并利用已有的加速器平台，实验验证了经过分束之后的激光可以产生2.30ns的电子束脉冲，电子束的加速能量和空间位置通过了分幅相机和扫描相机的测试。.基于该技术，研究人员科研进一步对激光脉冲的横纵向分布进行操控，产生所需的时间空间分布特性的激光脉冲。.该技术可以用于光阴极注入器产生百MHz重频的电子束，以满足产生更高品质的电子束从而产生更高品质的XFEL激光。