Dynamic properties of a small-size streak tube
Dynamic properties of a small-size streak tube
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DOI：
10.7498/aps.65.018502
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发表时间：
2016-01
期刊：
影响因子：
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通讯作者：
Hu Dandan;Tian Jinshou;Wang Junfeng;Lu Yu;Wen Wen-long-Wen;Xu Xiangyan
中科院分区：
文献类型：
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作者：
Hu Dandan;Tian Jinshou;Wang Junfeng;Lu Yu;Wen Wen-long-Wen;Xu Xiangyan
基于条纹相机的无扫描（闪光）激光雷达系统能够实现三维多光谱荧光成像和三维成像偏振测量。与传统的激光雷达系统相比，闪光激光雷达系统克服了目标与传感器平台之间的运动引起的图像失真。闪光激光雷达系统的其它优点是较高的图像更新速率和用于创建小型化激光雷达系统的潜力。为适应这一新技术的发展要求，利用计算机模拟技术（cst）软件，设计了一种超小型、大面积球形阴极无网格条纹管。具有近28 mm宽的光阴极工作区域的管包含两个静电聚焦透镜、一对偏转板和50 mm直径的输出屏幕。该管的外部尺寸仅为50 mm × 100 mm，并且其电磁场是在CST Particle Studio中基于有限积分理论计算的。通过观察从阴极上的多个不同点发射的不同电子轨迹，分析了管的一些动态特性。分析了偏转器位置对偏转灵敏度和空间分辨率的影响。增加偏转器和阳极针孔之间的距离导致更差的偏转灵敏度，但是导致更好的空间分辨率。在时间分辨率方面，条纹管在动态模式下可以很好地分辨出间隔为30 ps的三个电子脉冲。因此，条纹管的动态时间分辨率优于30 ps。并且通过估计电子轨迹的调制传递函数，可以在光阴极上的28 mm长的狭缝上获得10 lp/mm的空间分辨率。计算了整个光阴极工作区的时间畸变，结果表明光阴极工作区越大，时间畸变越大。时间失真也主要存在于光电阴极到偏转板的区域中。此外，还对条纹管在动态工作模式下的狭缝像进行了仿真。分析了由于时间畸变而导致狭缝图像弯曲的现象。两个相隔50 ps的矩形电子脉冲被条纹管很好地分辨。因此，这种小型牛排管的时间分辨率优于50 ps，其光电阴极上的矩形狭缝尺寸为30 mm × 50 μ m，其电光放大率为1.2。
Scannerless (flash) lidar system based on streak camera is able to realize three-dimensional (3d) multi-spectral fluorescence imaging and 3d imaging polarimetry. compared with conventional lidar system, the flash lidar system overcomes image distortions caused by the motion between the target and the sensor platform. other advantages of the flash lidar system are higher image update rates and the potential for creating a miniaturized lidar system. to meet the requirements for developing this new technology, a super small-sized, large photocathode area and meshless streak tube with spherical cathode and screen is designed with the aid of computer simulation technology (cst) software. the tube with nearly 28 mm wide photocathode work area contains two electrostatic focusing lens, a pair of deflection plates, and a 50 mm diameter output screen. the external dimension of the tube is merely 50 mm x 100 mm. and its electromagnetic fields are calculated in the cst particle studio based on the finite integration theory. some dynamic properties of the tube are analyzed via observing different electron trajectories launched from a number of different points on the cathode. the influences of the deflector position on deflection sensitivity and spatial resolution are analyzed. increasing the distance between the deflector and the anode pin hole leads to a worse deflection sensitivity but a better spatial resolution. as for the temporal resolution, three electron pulses separated by 30 ps can be well resolved by the streak tube in the dynamic mode. thus, the dynamic temporal resolution of the streak tube is better than 30 ps. and a 10 lp/mm spatial resolution across the 28 mm long slit on the photocathode can be obtained by estimating modulation transfer functions of the electron trajectories. temporal distortions at the entire photocathode working area are evaluated, and the data reveal that the larger the photocathode working area, the bigger the temporal distortions are. also, the temporal distortion is present mainly in the photocathode-to-deflection plates region. in addition, the slit image of the streak tube working in the dynamic mode is simulated and presented. the phenomenon that the slit image is curved due to the temporal distortion is analyzed. two rectangular electron pulses separated by 50 ps are well resolved by the streak tube. therefore, the temporal resolution of this small-size steak tube is better than 50 ps with a rectangular slit dimension of 30 mm x 50 mu m on the photocathode, and its electron-optic magnification is 1.2.