改型wiggler高次谐波自由电子激光的非线性理论分析

NONLINEAR ANALYSIS OF HIGHER HARMONIC FREE-ELECTRON LASER WITH MODIFIED WIGGLER

建立了改型wiggler自由电子激光的非线性理论,导出了自洽非线性方程组.用计算机模拟方法对改型wiggler 高次谐波自由电子激光进行了分析,得到了电子在与光场相互作用,从线性调制到非线性饱和演化过程中的相空间群聚图、高次谐波的增益、抽取效率以及电子束能谱图,同时,还研究了电子束能散度对高次谐波的增益和效率的影响等.模拟结果证实了改型wiggler自由电子激光是实现短波长相干光辐射的重要途径之一.

We have investigated the nonlinear theory of the modified wiggler free-electron laser and deduced a set of nonlinear self-consistent equations. We simulated the evolutional process of electrons interact with the optical field in a modified wiggler from linear modulation to nonlinear saturation, and got the bunching plot of electron phase space, gain of higher harmonics, extraction efficiency, and electron distribution function. We also studied the influence of electron energy spread on gain and efficiency of higher harmonics. Simulation results verifies that a modified wiggler free-electron laser is an important way to realize short-wavelength coherent radiation.