相对论速调管放大器中自洽的非线性理论与粒子模拟的比较

摘要

分别给出了归一化调制电流和电子束动能的积分微分方程,并提出了完整的数值计算方法。对于束压束流分别为511 kV,5 kA 和800 kV,8 kA 两组典型参数,采用非线性理论和二维粒子模拟程序分别计算了电流调制系数和距离的关系。在线性增长区以及当调制电流达到最大值并开始缓慢下降后,理论与模拟都符合得很好。此外还计算了电子束动能和调制电流的 n 次谐波的模式强度随归一化距离的变化情况：一次和二次谐波强度较大,八次以上谐波幅度较小而可以忽略。%This paper presents a self-consistent nolinear theory and gives the integrodifferential equations of the instantane-ous current and the beam kinetic energy.For two groups of typical parameters,the coefficients of current modulation versus the propagation distance were calculated by the numerical method and 2D-PIC code.The kinetic energy of the beam and the mode strength C n versus the propagation distance were also calculated and analyzed.The results of the simulation are consistent with the results of the nonlinear theory.