阴极门控光学条纹相机

为满足惯性约束聚变（ICF）物理实验诊断中对高信噪比低噪声光学条纹相机的需求，基于六电极同轴型扫描变像管发展了一种阴极门控光学条纹相机。该相机通过阴极预置直流高压叠加门控脉冲电压的方法，使相机变像管电压只有在门控脉冲加载时间内处于正常工作状态，才能对阴极发射的电子进行正常聚焦扫描，而在非加载门控脉冲时间内，变像管的第二聚焦电极处电压低于阴极电压，从而使阴极发射的光电子被反向截止，因此相机只对在门控脉冲加载时间内到达的有用信号进行测量，从而有效抑制了光学条纹相机受环境光辐照而引入的背景噪声，提升了相机的信噪比。验证实验表明，通过在阴极上加载幅度?5.5 kV、脉宽203 ns的门控脉冲电压，即可较大程度降低相机噪声，同时可维持相机的空间分辨率。

Optical streak camera with gated photocathode

In order to meet the demand for high signal-to-noise ratio and low-noise optical streak camera in inertial confinement fusion (ICF) physical experiment diagnosis, a cathode-gated optical streak camera with six electrodes streak image tube was developed. To suppress the camera noise, a method that loading DC high voltage while superimposing gated high voltage pulse to the photocathode was used. In this way, the streak image tube of the camera was in the normal working state only during the gated pulse loading time, and the electrons emitted by the cathode could be normally focused and scanned. When the control pulse was not loaded, the voltage at the second focusing electrode could be lower than the cathode voltage, so that the photoelectrons emitted by the cathode would be reversely cut off. Therefore, the camera only measured the useful signals that arriving within the gated pulse loading time, thereby effectively suppressing the background noise introduced by the optical streak camera irradiated by ambient light, and improving the camera's signal-to-noise ratio. The verification experiment shows that by loading the gated pulse voltage with amplitude of ? 5.5 kV and pulse width of 203 ns on the cathode, the camera noise can be greatly reduced, and the spatial resolution of the camera can be maintained.