Effect of pro-proximity pulse voltage on the noise characteristics of generation III low-light-level image intensifiers

To improve the noise performance of low-ligh-level (LLL) image intensifiers, the evaluation of the noise characteristics of a typical generation III image intensifier has been made through the measurement of signal to noise ratio at the output end (SNRout) of this image intensifier in different work conditions. One of the most meaningful work is to discuss the effect of the pro-proximity pulse voltage applied between photocathode and microchannel plate (MCP) on the SNRout of a sample of LLL image intensifier (2008III138). The experimental result shows that the optimal values of voltage across GaAs photocathode and that across MCP are −300V and 800V, respectively. More importantly, the optimal values of high level, low level, and duty circle of the pro-proximity pulse voltage are −300V, 0.2V, and 60%, respectively. This research will provide a theoretical guide and experimental support for developing low noise LLL image intensifiers.