微通道板结构参数对噪声因子的影响

采用对比测量方法研究了微通道板结构参数,即开口比、板厚、电极深度、离子阻挡膜、输入增强膜对其噪声因子的影响。结果表明,开口比增大,噪声因子减小;板厚增加,噪声因子增加;输入电极深度增加,噪声因子增加;离子阻挡膜会增加噪声因子;输入增强膜会降低噪声因子。其中,离子阻挡膜对噪声因子的影响最大,板厚对噪声因子的影响最小。微通道板的结构参数不仅对噪声因子产生影响,而且对其他参数,如增益、均匀性等性能均会产生影响。要降低微通道板噪声因子,比较可行的方法是将微通道板的开口比提高到68%,在此基础上,再在微通道板的输入端制作一层高二次电子发射系数的MgO2输入增强膜,使微通道板的噪声因子接近1,从而达到理想微通道板的水平。

Influence of Microchannel Plate Structure Parameters on Noise Factor

The influences of structure parameters of microchannel plate,such as opening area ratio,thickness,electrode depth,ion barrier film and input enhancement film on noise factor,were studied by comparative measurement method.The results show that the noise factor decreases with the raising of opening area ratio;increases with the raising of thickness;increases with the raising of input electrode depth;increases by ion barrier membrane;decreases by the input enhancement film.The influence of ion barrier film on noise factor is the most,and the influence of thickness on noise factor is the least.The structure parameters of microchannel plate not only affect the noise factor,but also affect other parameters such as gain and uniformity.In order to reduce the noise factor of microchannel plate,the most feasible method is to increase the opening area ratio to 68%,and then make a layer of MgO2 on the input end of microchannel plate.This will reduce the noise factor of microchannel plate close to 1 behaved in the ideal microchannel plate.