Abstract:
To reduce scattered noise which results from photons reflected by transparent or semitransparent photocathode at input surface of microchannel plate (MCP), the qualitative analysis of its influence on reflectance of the MCP input surface electrode and the test investigation of electrode film coating, film thickness, electrode depth, and open area ratio of MCP were given. Based on the influence of MCP input electrode on other MCP parameters, a technical solution was obtained which adopted electron gun to heat Ni-Cr alloy for electrode film coating and implemented the control of film thickness by keeping a constant resistance of 100, the electrode depth in channel accounted for 35% of channel diameter and the open area ratio of MCP was as larger as possible. Finally, the reflectivity of MCP input surface electrode is reduced to less than 4% and the photon scattered noise of image intensifier is decreased.