Relation between signal-noise-ratio of UV image intensifier and voltage of MCP

摘要

A system of signal-to-noise ration (SNR)tester for LLL image intensifier is reconstructed . To realize SNR tester for UV image intensifier,the signal processing module and measurement software of the tester are reconstructed.The system of UV optical path is used. Based on photoemission mechanism of photocathode, noise factor of photocathode is concerned with quantum yield. In a range,noise factor of micro-channel plate(MCP) is decreased with the increase in gain. For a fixed size micro channel,the gain of MCP is increased as the voltage of MCP rises. The analyzed results show that when the voltage of MCP is in the range of -700V～-850V,the noise factor is monotonically decreased,when it exceed -850V, MCP is saturated. Although gain has continued to increase, noise factor is in the state of saturation. Experiment platform is builded according to SNR tester principle diagram of UV image intensifier.The results are given and analyzed. The conclusion is proved that the effect of voltage of MCP on the SNR of UV image intensifier is compatible with the analysis of theory.