Research on calculation of cathode electron scattering radius in the generation III image intensifier

In the proximity focusing imaging system, the clear degree of images characterized by electronic scattering radius which could directly decide the resolution. In generation Ⅲ image intensifier, ion barrier film on the input of MCP is a serious influence factor on device resolution due to its electron scattering process. In this paper the electronic scattering radius would calculate at the single electron scattering, large electron scattering, and having ion barrier film electron scattering. Through comparing, it is found that the electron scattering radius is significantly larger at having an ion barrier film on the input of MCP. The results of calculation show that reducing the gap cathode-MCP and increasing the cathode voltage could reduce electron scattering radius, so as to improve the resolution of generation Ⅲ image intensifier.