基于电子轰击式CCD的大动态条纹相机研究

为了实现对更弱、以及物理量跨度更大的信号探测, 满足材料、生物、信息、半导体物理以及能源等重大科学领域对诊断精密化的进一步需求, 需要提高条纹相机的动态范围、空间分辨率和信噪比. 为此, 本文研制了基于电子轰击式CCD(EBCCD)的大动态条纹相机, 条纹变像管采用时间和空间方向分别聚焦的矩形框电极和电四极透镜结构, 可降低空间电荷效应. 并提高电子加速电压, 减小电子渡越时间以降低空间电荷相互作用时间. 采用基于电子轰击读出技术的背照式CCD(BCCD)作为读出器件, 取代传统的像增强CCD(ICCD)以缩短图像转换链, 较大地降低了超快诊断设备转换过程中的图像衰减, 从而提高条纹相机图像的信噪比、空间分辨率和动态范围. 实验得到静态空间分辨率高于35 lp/mm, 动态空间分辨率达到20 lp/mm, 偏转灵敏度为60.76 mm/kV, 动态范围达到2094:1, 扫描速度非线性为5.04%, 条纹相机的电子轰击半导体(EBS)增益达到3000以上.

Research on large dynamic range streak camera based on electron-bombarded CCD

In order to detect the weaker on greater span of light signals, the dynamic range, spatial resolution, and the signal to noise ratio of the streak camera need to be improved to meet further diagnostic requireflents in scientific area of materials, biology, information, semiconductor physics and energy, etc. Therefore, we design a streak camera with a larger dynamic range based on electron-bombarded CCD. Using the rectangle-framed electrode and electric quadruple lens in the streak camera can reduce its space charge effect and shorten the space charge interaction time by improving electron accelerating voltage to minimize the electron transit time. Using a back-illuminated CCD, which is based on the electron bombardment readout technology as image device to replace the traditional intensified CCD can shorten the chain of image conversion and greatly reduce the image degradation in the conversion of ultrafast diagnostic equipment. The signal to noise ratio, spatial resolution and dynamic range of the streak camera may gain improvement. Experimental results show that the static spatial resolution is better than 35 lp/mm and the dynamic spatial resolution is up to 20 lp/mm. Deflection sensitivity is 60.76 mm/kV and dynamic range reaches 2094: 1. Nonlinear scanning speed is 5.04%. EBS gain of the streak camera can be over 3000.