基于各向异性及后加速技术的百飞秒时间分辨条纹管设计  

100-fs time-resolved streak tube design based on anisotropy and post-acceleration technology

作　　者：田丽萍 沈令斌 陈萍[2] 刘玉柱 陈琳 惠丹丹[2] 陈希儒 赵卫[2] 薛彦华 田进寿[2] Tian Li-Ping;Shen Ling-Bin;Chen Ping;Liu Yu-Zhu;Chen Lin;Hui Dan-Dan;Chen Xi-Ru;Zhao Wei;Xue Yan-Hua;Tian Jin-Shou(School of Network and Communication Engineering,Jinling Institute of Technology,Nanjing 211169,China;Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology,Xi’an Institute of Optics and Precision Mechanics of Chinese Academy of Sciences,Xi’an 710119,China;School of Atmospheric Science,Nanjing University of Information Science&Technology,Nanjing 210044,China)

机构地区：[1]金陵科技学院网络与通信工程学院,南京211169 [2]中国科学院西安光学精密机械研究所,中科院超快诊断技术重点实验室,西安710119 [3]南京信息工程大学大气科学学院,南京210044

出　　处：《物理学报》2023年第24期302-311,共10页Acta Physica Sinica

基　　金：2022年度江苏省高等学校基础科学(自然科学)研究面上项目(批准号:22KJD140003);中国科学院科研仪器设备研制项目(批准号:GJJSTD20220006);中国科学院战略性先导科技专项A类(批准号:XDA25030900)和中国科学院青年创新促进会(批准号:2021402)资助的课题。

摘　　要：减小空间电荷效应及扫描偏转系统边缘场效应引起的时间弥散是实现百飞秒级时间分辨条纹管的关键.本文提出并设计了一种新型飞秒条纹管,结合超高加速电场、高扫描速度和后加速电场的设计,可在光电阴极4 mm×10μm的范围内实现100 fs量级的时间分辨率.通过优化设计加速电极结构,使光电阴极有效探测范围内的电子均可在15 kV/mm量级的强电场中加速运行,有效地抑制了电子脉冲的物理时间弥散;在阳极入口处放置窄狭缝以减小大角度光电子引起的时空弥散对性能的影响;最后在荧光屏处设置+5000 V的高电位,以缩短光电子在等位区的渡越时间,进一步减小空间电荷效应引起的时间弥散.最终,此设计方法能够将条纹管的时间分辨率提高至百飞秒量级.Reducing the space charge effect and the time dispersion caused by the edge field effect of the scanning deflection system is the key to realizing a 100-fs streak tube.In this paper,a novel fs streak tube is proposed and designed.The factors affecting its temporal resolution are analyzed theoretically and the specifications are given.Parameters including the electric field distribution and electron transmittance of the two common acceleration systems(planar cathode-mesh accelerating electrode and planar cathode-slit accelerating electrode)are compared with each other and analyzed theoretically.The results show that although the electric field distribution formed by the planar cathode(mesh accelerating electrode)can form uniform electric field,the electron transmittance is very low;planar cathode-slit accelerating structure will defocus the photoelectron beam along the scanning direction,but the electron transmittance in the effective detection range of the cathode is as high as 100%.The defocusing of the photoelectron beam can be removed by setting a narrow slit in front of the anode.The focusing electrode adopts two sets of plate-like structures which are vertically positioned in front and back to form a one-dimensional focusing electric fields along the scanning direction and the slit direction,respectively.The spatial focusing electrode is arranged close to the phosphor screen,which is beneficial to pushing back the cross-point of the electron beam along the spatial direction.Thus,the electron transit time dispersion in the condition of large electron density will decrease.At the same time,the anode can provide a post-accelerating voltage of+5000 V,which is beneficial to shortening the transit time and dispersion of the photoelectrons,thereby improving the temporal resolution.Based on the above theoretical analysis,a novel femtosecond streak tube is designed by using the planar cathode-slit accelerating electrode,anisotropic focusing system and post-accelerating method.The influence of the anode slit width on

关 键 词：各向异性聚焦技术 后加速技术 时间分辨率 飞秒条纹管 

分 类 号：O462[理学—电子物理学]