微光像增强器信噪比与MCP电压关系

Relation between signal-to-noise ratio of LLL image intensifier and voltage of MCP

为了揭示微通道板电压的变化对微光像增强器信噪比的影响,进一步优化像增强器的性能,分别测试出超二代和三代微光像增强器的信噪比随微通道板的电压变化曲线,前者在微通道板电压为600 V^800 V时,信噪比单调增加到25.9,在800 V^900 V时,信噪比在25上下震荡并呈下降趋势,在900 V^1000 V时,迅速下降到21.8;而后者当M CP电压在800 V^1000V时,单调增加到27.87,在800 V^1180 V时,则在26.61~28.66之间震荡。通过对微通道板噪声因子的理论分析,指出进一步降低微通道板噪声因子,改善微光像增强器信噪比的方法。

In order to reveal the influence of the voltage variation of microchannel plate on the signal-to-noise ratio of LLL image intensifier and optimize the performance of the image intensifier, the curves that the signal-to-noise ratio of super Gen Ⅱ and Gen Ⅲ image intensifiers variates with the voltage of a microchannel plate were obtained by the aid of a signalto-noise ratio tester. As for the super Gen Ⅱ image intensifier, when the microchannel plate＇s voltage is in the range of 600- 800 V, the signal-to-noise ratio is monotonically increased to 25.9, when it is in the range of 800-900 V, the ratio is 25 or so and has downtrend, and when 900-1 000 V, the ratio is rapidly decreased to 21.8. As for the Gen Ⅲ image intensifier, when the microchannel plate＇s voltage is in the range of 800- 1 000 V, the signal-to-noise ratio is monotonically increased to 27. 87, and when the voltage is in 1 000- 11 800 V, the ratio fluctuates from 26. 61 to 28.66. In combination with the theoretical analysis of microchannel plate＇s noise factor, a method to reduce the noise factor of microchannel plates and improve the signal-to-noise ratio of LLL image intensifiers is proposed.