毫米波自由电子激光的数值模拟和实验的比较

从波导管毫米波自由电子激光器的设计要求出发,根据Livermore实验室FRED程序的物理思想,编制了空间三维的数值模拟程序(WAGFEL)。为了检验程序的可靠程度,结合ELF装置的实际参数,进行了数值模拟并和实验结果进行了比较。结果表明,把Wiggler磁场B_w增大300 Gs后,WAGFEL程序的模拟结果和Livermore实验室的实验结果基本符合。模拟使用的全部参数,除B_w增大300Gs外,都是ELF的实际参数。模拟时峰值磁场B_w=4050Gs,实验测量峰值磁场B_w=3720Gs,相差在8％左右。WAGFEL程序可以用来从事毫米波自由电子激光器的设计以及基本物理问题的研究。

COMPARISION OF MICROWAVE FEL NUMERICAL SIMULATIONS WITH EXPERIMENTAL DATA

In this paper, we compare microwave FEL numerical simulations using our code named WAGFEL which is a three-dimensional code, with the experimental data of Livermore Laboratory. WAGFEL evolves the electrons' energies and ponderomotive phase according to the averaged single -particle equations derived by KMR. and the fields according to the paraxial wave equation with the source term as derived byColson. The particle motion is fully three-dimensional. The field solver is two-dimensional, because only the lowest TE01 mode is considered in the rectangular waveguide. In order to obtain good agreement between experiment and theory, the code must include the effect of the longitudinal space-charge force in the KMR equations, the effect of v2