Particle simulations of a finite‐length free electron laser
Particle simulations of a finite‐length free electron laser
复制标题
有限长度自由电子激光器的粒子模拟
DOI：
10.1063/1.863540
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发表时间：
1981
影响因子：
4.6
通讯作者：
M. Caponi
中科院分区：
文献类型：
--
作者：
P. Liewer;A. T. Lin;J. Dawson;M. Caponi
有限长度自由电子激光器的一维粒子模拟表明，对流不稳定的短波长模式是与模式的增长长度相比长的系统最初的主要不稳定性。此外，有限长度系统的广义一维线性理论已经推导出包括所有动力学效应。在模拟中看到的不稳定模式和该理论预测的模式之间的比较是很好的协议。然而，模拟显示出显着更高的效率比理论预测时，捕获由单一模式的饱和机制。这可能是由局部直流电场（空间电荷场）引起的，该电场随着光束减速而自洽地产生。
One‐dimensional particle simulations of a finite‐length free electron laser show that the convectively‐unstable, short‐wavelength mode is the dominant instability initially for systems long compared with the growth length of the mode. Also, a generalized one‐dimensional linear theory of a finite length system has been derived with all kinetic effects included. Comparison between the unstable modes seen in the simulation and those predicted by this theory are in good agreement. However, the simulations show a significantly higher efficiency than that predicted by the theory when trapping by a single mode is the saturation mechanism. This may be caused by a local dc electric field (space charge fields) that arises self‐consistently as the beam slows down.