优化脉冲间距的多脉冲尾流加速PIC模拟

多脉冲激光尾波场加速电子方法中限制尾波场振幅的主要机理是“相位失谐”,起源于非线 性效应导致尾波波长随振幅的增长而变大,从而后续脉冲逐渐偏离加速相位. 借助2D3V PIC 模拟方法优化各脉冲之间的间距,使之等于前面脉冲激发的尾波波长,模拟结果表明激发了 更大振幅的尾波场,同时激发了更强的“前向Raman散射”,它在限制尾波场进一步增长的 过程发挥了重要作用. 关键词：多脉冲激光尾波加速有质动力相位失谐前向Raman散射

PIC simulation of the wake field accelerator driven by multiple-pulse with optim ized intervals

The so-called !phase detune", caused by nonlinear effects which increase the wavelength of the wake wave, when its amplitude exceeds some limitation, is the main saturation mechanism of wake waves in multiple pulse laser wake-field accelerator(MP-LWFA). The MP-LWFA with the optimized spacing between the pulses equal to the wavelength of the wake wave, is studied by PIC simulation in this paper. Our simulation indicates that the detuning length and thus the amplitude of the wake wave increases as our expected. Furthermore, the stronger forward Raman scattering is stimulated, which plays an important role in stopping the increase of wake waves.