MCP像增强器开门/关门时间特性研究  

The Study of Turn on / turn off Gated MCP Image Intensifier

作　　者：谢红卫[1] 陈进川[1] 李宏云[2] 褚衍运[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川621900 [2]西北核技术研究所,西安710025

出　　处：《核电子学与探测技术》2014年第10期1196-1200,共5页Nuclear Electronics & Detection Technology

基　　金：国家自然科学基金(11005095;1305155)

摘　　要：门控型MCP像增强器具有光选通和图像增强两个作用,与CCD器件耦合组成高灵敏度高速图像记录系统,广泛应用于惯性约束核聚变研究中的时空分辨图像诊断。开门时刻和关门时刻叠加在MCP像增强器的光电阴极上的选通电压具有较强的"孔栏"效应,"孔栏"效应时间在ns级时间范围内,在ns级时间分辨图像诊断中对图像轮廓强度分布影响较大。本文首先从理论上分析了引起"孔栏"效应的物理过程,并进行了模拟计算[1],然后进行相关的实验研究。在实验中使用波长为532 nm、脉冲宽度约为300 ps的脉冲激光作为光源,实验测量MCP像增强器的开门/关门时间,实验结果表明:双紧贴MCP像增强器的开门时间和关门时间约为1.8 ns,对于半宽度约为20ns电脉冲信号,MCP曝光开门时间约为30 ns,电脉冲宽度与实际曝光时间具有一定的差异。进一步的理论分析表明,为了获得亚ns级以下的时间分辨图像,需要采用单紧贴MCP像增强器或增加导电基体的厚度以牺牲荧光透过率等技术途径。The gated image intensifier has two function ,light gating and image enhancement .Coupled with a CCD device , it can constitute a high -sensitivity and high -speed image recording system , widely used in space and time resolved image diagnosis of inertial confinement fusion research .The photocathode gating voltage superimposed by the gate opening and closing time has a strong ＂limiter＂effect ,which effects time within ns level , deeply affecting the image contour intensity profile in ns level time -resolved image diagnosis .This pa-per firstly analyzes theoretically the physical process leading the ＂limiter＂effect , and carried out a simulation calculation [1] .Then some related experimental research was conducted .In the experiment , a pulsed laser with a wavelength of 532 nm and a pulse width of 300 ps is used as the light source .This experiment measures the o-pening /closing time of the image intensifier .The result shows that , the opening and closing time of the double tightly-stuck MCP image intensifier are approximately 1.8ns;for electrical pulses with a half -width of nearly 20ns, the exposure opening time of the MCP is about 30ns, demonstrating that the pulse width and the actual exposure time exist a certain difference .Further theoretical analysis indicates that in order to obtain a below sub-ns resolved image , we need a single tightly-stuck MCP image intensifier or to increase the thickness of the conductive substrate to sacrifice fluorescence transmission ratio as well as using other technical approaches .

关 键 词：门控型MCP像增强器 光快门 传输线 时空分辨 

分 类 号：O462.3[理学—电子物理学]