Effect of Microchannel Plate Tilt Angle on Image Intensifier Performance

The effects of the microchannel plate (MCP) tilt angle on the MCP noise factor, resolution, and gain of an image intensifier was studied through an experimental comparison and analysis. The results showed that the relationship between the MCP noise factor and MCP tilt angle was parabolic when the MCP tilt angle was in the range of 5°–12°. The MCP noise factor was the smallest when the MCP tilt angle was 9°, and the resolution was negatively correlated with the MCP tilt angle. The resolution was the largest when the tilt angle of the MCP was 5°. The MCP gain changed parabolically with an increase in the MCP tilt angle. The MCP gain was the largest when the MCP tilt angle was 9°. Because the direction of the photoelectrons emitted by the photocathode of the image intensifier is certain, changing the MCP tilt angle causes the photoelectrons to enter the front end of the MCP channel at a different angle. This results in different secondary electron emission layer depths, such that the number of secondary electrons and the radius of the scattering spot formed by the electrons at the output end are different. To determine the best MCP tilt angle, the main performance requirements of an image intensifier under various usage scenarios must be comprehensively considered.