Research of High Quality Electron Beam and THz-FEL Based on Numerical Simulation for Electromagnetic Fields Employing a 3-D FDTD Method

基于 3-D FDTD 方法电磁场数值模拟的高质量电子束和 THz-FEL 研究

• 批准号: 17360035
• 负责人: HAMA Hiroyuki
• 金额: $ 9.62万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17360035/
• 关键词: FDTD method; high-brilliant electron beam; free electron laser; numerical simulation; RF gun; Terahertz radiation; Smith-Purcell radiation; femto-second electron beam; 時間領域差分(FDTD)法; コヒーレント放射; 空間電荷効果; バンチ圧縮; 熱陰極; 速度集群効果

In this research work, we have investigated concerning high-brilliant electron beam and free electron laser (FEL) oscillation by means of numerical simulation employing Finite Difference Time Domain (FDTD) method as a Maxwell's equations solver. As a first step, beam characteristics produced by a thernionic RF gun was studied by the FDTD simulation. Results of the work have improved design work of the actual RF gun. In the 2nd year, the beam optics for the bunch compression has been optimized by using results of the FDTD simulation, then it was found that there would be a possibility of producing very short electron bunch length around 70 femto-second. In addition, properties of coherent synchrotron radiation in Terahertz region were studied theoretically and a basic layout of light source accelerator has been designed. As the simulation code has been progressed, the beam dynamics in a bunch compressor was precisely evaluated by taking the effect of space charge into account. As the result the possibility of producing 100 femto-second beam bunch and its application for a new accelerator based coherent light source were pointed out.Meanwhile lasing of Smith-Purcell backward wave oscillator (BWO) FEL using a low energy DC beam was successfully simulated by using the FDTD code. It was found that the dc beam having the normalized emittance less than 1 mm mrad and the kinetic energy of less than 50 keV is required for Smith-Purcell BWO FEL. This source is concluded to be very promising and unique for future narrowband intense sub-Terahertz radiation.

本论文采用时域有限差分法（FDTD）作为麦克斯韦方程求解器，对高亮度电子束和自由电子激光振荡进行了数值模拟研究。作为第一步，通过FDTD模拟研究了热离子射频枪产生的波束特性。研究结果对实际射频电子枪的设计工作具有一定的指导意义。在第二年，束团压缩的光束光学已经通过使用FDTD模拟的结果进行了优化，然后发现有可能产生非常短的电子束团长度约为70飞秒。此外，还对太赫兹相干同步辐射的特性进行了理论研究，设计了光源加速器的基本布局。随着模拟程序的发展，考虑空间电荷的影响，束团压缩器中束流的动力学特性得到了精确的计算。指出了产生100飞秒激光束团的可能性及其在基于加速器的新型相干光源中的应用，同时利用FDTD程序成功地模拟了利用低能直流光束的Smith-Purcell返波振荡器（BWO）自由电子激光器的激射。结果表明，Smith-Purcell返波自由电子激光器所要求的直流束流的归一化发射度小于1 mmmrad，动能小于50 keV。这个来源的结论是非常有前途的和独特的未来窄带强亚太赫兹辐射。

项目成果

DEVLOPMENT OF A LOW EMITTANCE DC GUN FOR SMITH-PURCELL BWO FEL

为 SMITH-PURCELL BWO FEL 开发低发射直流电子枪

• 发表时间: 2007
• 期刊: Proc. 29th International Free Electron Laser Conference, Novosibirsk, Russia 1
• 作者: K. Kasamsook;K. Akiyama;K. Nanbu;M. Kawai;F. Hinode;T. Muto;T. Tanaka;M. Yasuda. Y. Mori;H. Hama
• 通讯作者: H. Hama

Simulation study of a thermionic rf gun for high brightness and short pulse beam

高亮度短脉冲光束热离子射频枪仿真研究

• 发表时间: 2005
• 期刊: Proc. 21st Particle Accelerator Conference 1
• 作者: T. Tanaka;F. Hinode;M. Kawai;A. Miyamoto;K. Shinto;H. Hama
• 通讯作者: H. Hama

Beam quality measurements of a low emittance dc gun employing single crystal of LaB_<66> cathode

采用单晶 LaB_<66> 阴极的低发射率直流电子枪的光束质量测量

• 发表时间: 2007
• 作者: K. Kasamsook;K. Akiyama;K. Nanbu;M. Kawai;F. Hinode;T. Muto;T. Tanaka;M. Yasuda;Y. Mori;H. Hama
• 通讯作者: H. Hama

Study and development of a thermionic ITCRF gun for production of ultra-short electron bunches

用于产生超短电子束团的热电子ITCRF枪的研究和开发

• 发表时间: 2006
• 作者: T. Tanaka;M. Kawai;F. Hinode;T. Muto;K. Nanbu;K. Kasamsook;K. Akiyama;M. Yasuda;H. Hama
• 通讯作者: H. Hama

Super coherent THz light source based on an isochron ous ring with very short electron bunches

基于具有极短电子束的等时环的超相干太赫兹光源

• 发表时间: 2006
• 期刊: Proc. 28th International Free Electron Laser Conference 1
• 作者: T. Tanaka;T. Muto;F. Hinode;M. Kawai;K. Nanbu;K. Kasamsook;K. Akiyama;M. Yasuda;H. Hama;H. Tanaka
• 通讯作者: H. Tanaka