Multi-alkali Photocathode Thermal Performance Analysis of Image intensifier Based on Low-high Temperature Environment Testing Conditions

摘要

Low-level-light (LLL) weapon sight measurement technologies based on Low-high temperature environments testing conditions are always concerned by military equipments manufacturers. Because low-high temperature environment, etc. are under loaded function , the electric performance parameter change to make LLL weapon sight, causing the LLL weapon sight can't be worked and used normally while taking aim. Generally believed that many photocathode is n-type and p-type doping of the inner surface layer comprising more photocathode not light sensitive, but also sensitive to temperature. To image intensifier is non-working state at the temperature 70°C ± 2°C test boxes and thermostats time one hour, five minutes to image intensifier into - 50°C ± 2°C Test Box temperature one hour, then five minutes again placed 70°C ± 2°C high temperature test box for three cycle question image intensifier restore normal temperature after the test. The experiments show that, when the temperature rises, the heat semiconductor photocathode current density, thermal current rise in the temperature range 0 to 70°C , 4°C temperature is increased, almost twice its current heat. Of course, image intensifier imported the equivalent background illumination will also increase, resulting in night vision systems observed at the scene image contrast and differential rates were lowered, target detection system performance last night caused the decline. A study of the reasons is the photo-cathode materials and fabrication of thermal electron emission standards restricting the ability.