自由电子激光振荡器的三维数值模拟

THREE-DIMENSIONAL NUMERICAL SIMULATION OF FREE ELECTRON LASER OSCILLATOR

仔细地考查了与三维自由电子激光振荡器物理方程组相应的３－Ⅰ程序的可靠性。在此基础上使用该程序计算、分析了在电子束与光束同轴条件下，当电子束参数如能散度、发射度、束流等参量改变时三维自由电子激光的一些基本规律。

AbstractIn this paper,we examined first carefully reliability of 3-Ⅰcode correspondentphysical equations of FEL oscillator.The numerical simulation results of electron equationcoincide with analytical results when γ=const.The numerical results of root-square of theelectron beam coincide with analytical results.The numerical results of no-source waveequations coincide with not only analytical results,but also the amplitude and phase ofoptical field achieve self-reappear for pass number N_p=2.Under the same conditions of computation, the power P/MW and gain G_n/% as afunction of N_p computed by 3-Ⅰcode coincide with those computed by 3-Ⅱcode.Saturation power P_s/MW computed by 3-Ⅰcode is a little higher than that computed by3-Ⅱcode which is about 3%. Those results show that not only are 3-Ⅰcode correct.but also results are reliable. As a result we design experiments,simulate and analyzeexperimental results, and research physical problems of free electron laser by 3-Ⅰcode. We also presented possible way by which the results computed by 3-Ⅰcode coincidewith those computed by FELEX code of LANL. When we didn’t change the conditionsof the wiggler,oscillator parameter and electron beam shape,if we enhance l5% of thecurrent,the results obtained by 3-Ⅰcode accord with those bv FELEX code.When weenhanced 40% of the x-emittance and 30% of the current,the saturation power P,computed by 3-Ⅰcode accord with that computed by 3-Ⅲ.The second,under same axis condition between electron beam and optical beam, wecomputed and analyzed some of basic problems of FEL by 3-Ⅰcode when we changedelectron beam parameters such as energy spread,emittance and current et al.