We report a theoretical analysis and numerical simulation of the dynamics of transverse emittance of an electron bunch during its acceleration in wake fields generated by a laser pulse in a weakly nonlinear mode. Analytical expressions are obtained for the main factors affecting the emittance growth during acceleration and the case is considered when the characteristic transverse size of the injected bunch exceeds the matched radius determined by the focusing force at the injection point, the initial emittance and the electron bunch energy, and the resulting value of emittance is much larger than the initial one. The dynamics of the emittance growth during acceleration as a function of the length of the electron bunch is described, and the length of the bunch is found at which there occurs a complete phase mixing of betatron oscillations of electrons and the emittance increases to its maximum value determined by the bunch parameters and the focusing force at the injection point. An...

中文翻译：

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引导结构中激光等离子体加速过程中发射率与电子束长度的关系

我们报告了在弱非线性模式下由激光脉冲产生的尾波加速过程中电子束横向加速发射的动力学的理论分析和数值模拟。获得了影响加速过程中发射率增长的主要因素的解析表达式，并考虑了当注入束的特征横向尺寸超过由注入点的聚焦力，初始发射率和电子束能量确定的匹配半径时的情况，并且发射率的结果值比初始值大得多。描述了加速过程中发射率随电子束长度变化的动态变化，并发现束的长度，在该处发生电子的电子加速器振荡的完全相混合，并且发射率增加到由束参数和注入点处的聚焦力确定的最大值。一个...