Influence of input electrode of micro-channel plate on opening area ratio and its improvement

As a key electron multiplier, the micro-channel plate is widely used in many fields. The effect of NiCr film as the input electrode of micro-channel plate on the opening area ratio of micro-channel plate was analyzed. A theoretical model was established, and the effects of coating thickness, coating depth and other parameters on the opening area ratio were calculated. Two kinds of coating research were carried out to reduce the loss of opening area ratio. One way, the process was adjusted to weaken the fractionation effect of alloy evaporation, reduce the resistivity of electrode film layer, and the loss of opening area ratio was reduced by about 2 percentage points. Another way was to change the coating method, the Ni and Cr metal were used to prepare laminated films, regulate the proportion of Ni and Cr in the coating process, increase the proportion of Ni in the input terminal electrode, and also reduce the resistivity of the electrode film. On the premise of meeting the surface resistance requirements, the input terminal film could be thinned to 86 nm. Compared with the conventional Ni-Cr alloy film with a thickness of 300 nm, the loss of the opening area ratio of the MCP input terminal was reduced by 3~4 percentage points, and the MCP gain was increased by 6%.