激光与光电子学进展, 2016, 53 (6): 061404, 网络出版: 2016-05-25
基于带状束的史密斯-帕塞尔自由电子激光模拟与分析 下载: 694次
Simulation and Analysis of Smith-Purcell Free Electron Laser Based on Sheet-Beam
激光光学 史密斯-帕塞尔效应 全反馈谐振腔 带状束 宽高比 laser optics Smith-Purcell effect full feedback resonator sheet-beam aspect ratio
摘要
采用三维数值模拟方法研究了基于带状束的史密斯-帕塞尔自由电子激光(S-P FEL)的辐射输出特性。当一束相对论带状束紧贴着矩形光栅表面飞行时,可以激励起非相干的史密斯-帕塞尔(S-P)辐射,而全反馈谐振腔可以将各个方位角的S-P辐射反射回带状束,同时进行速度调制,使电子注发生群聚,进而获得相干的S-P辐射。通过数值模拟发现,带状束可以提高S-P FEL的功率和功率谱密度;随着带状束宽高比的增大,电子束的速度调制和群聚更为明显,S-P FEL的功率和功率谱密度也越大。
Abstract
The radiation output characteristics of the Smith-Purcell free electron laser (S-P FEL) based on different sheet-beams are studied by the three-dimensional numerical simulation. As a sheet-beam flies closely to the rectangular gratings, it emits incoherent Smith-Purcell (S-P) radiation. The full feedback resonator reflects the radiation with a random azimuth angle back onto the sheet-beam and causes the electrons to be modulated, which leads to electron bunching and coherent S-P radiation. The numerical simulation results show that the power and power spectrum density of S-P FEL can be increased by the sheet-beams. The modulation of sheet-beam, the bunching state of sheet-beam, and the power and power spectrum density of S-P FEL, all increase with the increasing aspect ratio of sheet-beam.
孟现柱, 王明红, 任忠民. 基于带状束的史密斯-帕塞尔自由电子激光模拟与分析[J]. 激光与光电子学进展, 2016, 53(6): 061404. Meng Xianzhu, Wang Minghong, Ren Zhongmin. Simulation and Analysis of Smith-Purcell Free Electron Laser Based on Sheet-Beam[J]. Laser & Optoelectronics Progress, 2016, 53(6): 061404.