针对高时空分辨的设计要求,分析影响条纹相机中条纹变像管的物理时间弥散、技术时间弥散和扫描电路触发晃动的因素,优化设计了行波偏转前置磁透镜聚焦的条纹变像管系统.利用CST仿真软件研究了行波偏转器内部的时变电磁场分布,计算了行波偏转器内电磁波的传播速度.结果表明,行波偏转器的指长为8mm、指宽为1mm、指间距为0.24mm、管脚长为2.5mm、板厚为1mm及总长度为17.12mm时,实现了电子团的飞行速度与扫描电脉冲沿行波偏转器的传输速度的匹配.采用电子追迹法和瑞利判据分析了条纹变像管的动态时间和空间特性,得到单次扫描动态时间分辨率为200fs、同步扫描时间分辨率为208fs、动态空间分辨率优于20lp/mm.
Aim to high temporal resolution of the streak image tube in streak camera,the factors which influence the physical temporal dispersion,technical temporal dispersion and time jitter of the sweep circuit were discussed.The streak image tube was optimized,in which a pair of traveling wave deflectors was located before a magnetic solenoid lens.The inner time-varying electric field of traveling wave deflectors was simulated by CST electromagnetic studio.And the propagation velocity of electromagnetic wave was calculated.The results show that when leg length is 8mm,leg width is 1mm,interval is0.24 mm,pin length is 2.5 mm,deflector thickness is 1 mm and deflector length is 17.12 mm,the moving velocity of electrons and propagation velocity of the electromagnetic wave are matching.Based on the electron trajectory tracing method and the Rayleigh criterion,dynamic temporal and spatial characteristics of the streak image tube were analyzed,a dynamic temporal resolution of 200 fs in single sweep mode,dynamic temporal resolution of 208 fs in synchronized sweep mode,and a dynamic spatial resolution of above 20lp/mm were obtained.