双束平行入射电子束引导的自注入电子加速效果的研究

摘要

在粒子束引导的等离子尾波场加速机制中，为了加速电子获得最大能量，大量研究集中于改变单束牵引粒子束的线度、形状、电荷性质等参数.综合考虑已有的实验结果，本文提出了一种相比于单束电子牵引更为有效的加速方式，利用双束平行电子束来加速自注入的电子.通过2.5维粒子程序模拟，发现在牵引电子束具有相同能量、电量、尺寸的条件下，通过双束平行电子束加速得到的电子具有长程加速、高能和准单能性的特性.同时在空泡内形成了一束独特的回流电子，进一步使得自注入电子具有更好的准直性.%In the case of wake field acceleration driven by charged particle bunches, many researchers focused on adjusting parameters such as magnitude, shape and electrical properties to amplify the maximum energy which drives electrons. Comprehensively considering the existing studies, in the paper we propose a new method of acceleration in which paralleled bunches are used to excite plasma wake field and trap self-injected electrons. It is proved to be more efficient than using single drive beam. With 2.5D PIC code, the driven electrons accelerated by paralleled bunches are found to possess the advantages of acceleration in longer distance, higher energy and better quasimonoenergy. Moreover, a bunch of backflow electrons is observed in the bubble, which makes self-injected electrons well collimated.