Research on Small Sized Free Electron Laser Using Hybrid Helical Microwiggler

混合螺旋微摆动器小型自由电子激光器研究

• 批准号: 09650057
• 负责人: TSUNAWAKI Yoshiaki
• 金额: $ 2.18万
• 依托单位: Osaka Sangyo University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650057/
• 关键词: free electron laser; wiggler; undulator; field emission; nanotube

Free electron laser(FEL) experiments have been done only in huge facilities containing high energy electron beam accelerator. This fact prevents many researchers from easy use of FEL. It is, therefore, very important to develop a very small scale FEL which can be used even in normal laboratory of university. This problem could be resolved for FEL as spectroscopic source with low power in the far-infrared to millimeter wave. In this study, we tried to develop each constituent of FEL as small as possible ; a microwiggler and an electron beam source based on field emission.A computer simulation analysis of wiggler field decided to manufacture a hybrid helical microwiggler constructed with four layers each period. Each layer consists of pentagonal permanent magnets and ferromagnets and is stacked along the wiggler axis rotating angle of 90°. The period and gap diameter of the wiggler are 10 and 5 mm, respectively. The wiggler field was measure to be 3.8 kG enough for FEL and could be adjus … More ted within 200 G. More uniform field will be, furthermore, accomplished by sorting of permanent magnets. The height of the wiggler of only 75 mm means one of the smallest microwiggler in the world. This wiggler also interested some researchers in short wavelength SASEFEL and gamma-gamma collider besides FIR FEL.In the field emission experiment, conventional tungsten wire was electrolytically etched to a needle for investigation. It was found from simulation and experiment that electron beam current was enlarged in a certain voltage range of 2nd gate depending on the cathode potential and the distance between 1st and 2nd gates. Four tungsten needles could be well arrayed. Bunched carbon nanotubes were also supplied to field emission source research. We could attain very high field emission current of 2.2 mA which is 〜100 times as high as that of W tip. The current fluctuation is also very small <4%. It would be said that our nanotubes have necessary properties for Cherenkov FEL or Smith-Purcell FEL at present time.Further studies are in progress to propagate the electron beam into the wiggler and emit the radiation. Less

自由电子激光（FEL）实验一直是在大型高能电子束加速器装置上进行的。这一事实阻碍了许多研究人员方便地使用自由电子激光。因此，研制一种小型的、甚至可以在大学普通实验室中使用的自由电子激光器是非常重要的。自由电子激光作为低功率的远红外-毫米波光谱源可以解决这一问题。在本研究中，我们尝试将自由电子激光器的各个组成部分都做得尽可能的小：微扭摆器和基于场致发射的电子束源，通过对扭摆器场的计算机模拟分析，决定制作一个每个周期有四层结构的混合螺旋微扭摆器。每一层由五边形永磁体和铁磁体组成，沿摇摆器轴旋转90°的角度沿着堆叠。摆动器的周期和间隙直径分别为10和5 mm。实验测得摇摆器磁场为3.8kG，可以调节 ...更多信息 在200 G以内。此外，通过对永磁体进行分类，将实现更均匀的磁场。摇摆器的高度仅为75 mm，是世界上最小的微摇摆器之一。在场致发射实验中，将传统的钨丝电解腐蚀成针状，并将其应用于短波长SASEFEL和γ-γ对撞机中。模拟和实验结果表明，在一定的第二栅电压范围内，电子束流随阴极电位和第一、第二栅间距的变化而增大。四根钨针可以很好地排列。成束的碳纳米管也被用于场发射源的研究。我们可以获得非常高的场发射电流2.2mA，是W尖的100倍。电流波动也很小<4%。可以说，目前我们的纳米管已经具备了切伦科夫自由电子激光（Cherenkov FEL）或Smith-Purcell自由电子激光（Smith-Purcell FEL）所必需的性质，进一步的研究正在进行中，以将电子束传输到摇摆器中并发射出辐射。少

项目成果

Y.Tsunawaki, M.Noguchi, M.Kusaba, N.Ohigashi, M.Fujita, K.Imasaki, S.Kuruma, K.Mima, S.Nakai, and C.Yamanaka: "Hybrid Planar Wiggler with a Period of 2 cm for Higher Harmonic FEL Lasing"Int. J. Infrared Millimeter Waves. 19(2). 117-184 (1998)

Y.Tsunawaki、M.Noguchi、M.Kusaba、N.Ohigashi、M.Fujita、K.Imasaki、S.Kuruma、K.Mima、S.Nakai 和 C.Yamanaka：“周期为 2 的混合平面摆动器

綱脇恵章,野口美枝,大東延久,藤田雅之,今先一夫,三間圀興: "ハイブリッド平面ウィグラーを用いた自由電子レーザーの高調波利得解析" レーザー研究. 26・5. 386-389 (1998)

Yoshiaki Tsunawaki、Mie Noguchi、Nobuhisa Daito、Masayuki Fujita、Kazuo Imazaki、Kuniyuki Mima：“使用混合平面摆动器的自由电子激光器的谐波增益分析”激光研究 26・5。

Y.Tokura, Y.Tsunawaki, M.Kusaba, N.Ohigashi, M.Fujita, K.Imasaki, and K.Mima: "Development of a Tungsten Field Emission Cathode for Free Electron Laser"Rev. Laser Eng.. 26(5). 390-394 (1998)

Y.Tokura、Y.Tsunawaki、M.Kusaba、N.Ohigashi、M.Fujita、K.Imasaki 和 K.Mima：“自由电子激光器钨场发射阴极的开发”Rev。

Y.Tsunawaki,Y.Tokura,M.Kusaba,N.Ohigashi,: "Simulation and Experimental Study on Tungsten Field Emission Cathode" Nucl.Instr.and Meth.(to be published). (1999)

Y.Tsunawaki，Y.Tokura，M.Kusaba，N.Ohigashi，：“钨场发射阴极的模拟和实验研究”Nucl.Instr.and Meth.（待出版）。

Y.Tsunawaki: "Wiggler for Free Electron Laser"J. Jpn. Soc. Infrared Sci. Tech. 7(1). 34-44 (1997)

Y.Tsunawaki：“自由电子激光摆动器”J。