三维FEL振荡器的数值模拟

A 3D SIMULATIONS OF FEL OSCILLATOR

在３８６微机上建立了三维ＦＥＬ单模，多模振荡器模拟程序，并用该程序进行了计算。发现：１．对单模，在足够多的振荡次数的条件下（ａ）非理想入射，发射度，能散度对激光饱和功率的影响程度在一定范围内不显著，而且随输出耦合系数的降低而变弱。在输出耦合为２％时，小程度的非理想入射的饱和功率反而超过正入射；（６）非理想入射对饱和情况下的激光品质的影响也不显著，并随输出耦合系数的降低而变弱。２．对多模，在高输出耦合的情况下，边带将受到抑制而不能增长。非理想入射、发射度都会减慢边带的增长。

A code for simulation of 3D FEL oscillator has been established on 386 PC.Using this code,several calculations were done as follows:1.In single mode cases,(a)the influ-ences of non-ideal injiction,emittance and energy spread on FEL saturated power in a certainregion arenot distinctive, moreover,they become weakened when output coupling is small.Speciallyin our calculation with output coupling 2%, the saturated power for slight degree of non-ideal in-jection exeeed that of ideal injection.(b)the influenees of non-ideal injection on optical beamquality are not severe,they also become weakened when output coupling is small.2.Inmultimodes(16)cases,the calculations show that side bands can not grow up when outputcoupling is large,and non-ideal injection, emittance can slow down the growth of side bands.