Performance characteristics of solar blind UV image intensifier tube

Abstract

The UV radiation of spectrum range of 200~320nm almost is zero on the earth surface because UV radiation is greatly absorbed by ozone in atmosphere. So this spectrum range is called “Solar Blind Range ”. Because Solar Blind UV(SBUV) can’t be influenced by atmosphere , it is easy to detect them as soon as SBUV radiation objects appear in the earth surface. If UV photoelectric image devices are used to observe them, high contrast picture will be acquired, that bright object’s image lie in full black background. It is easy to identify the picture by human eye or other optical sensor (CCD). A solar blind UV(Ultra Violet) image intensifier tube(SBUV-IIT) is a special image intensifier tube, which was developed on double proximity focused GenerationⅡ low-light-level image intensifier tube. It only responses spectrum range of 200~320 nm., SBUV-IIT can be used to observe UV faint radiation object, because UV sensitivity is high and response time is rapid and radiation gain is high. Low-altitude-flying missile can be observed by detecting its tail fog with SBUV-IIT, because its tail fog emits plenty of SBUV. By this way high contrast UV picture can be acquired to achieve missile warning, and this way has been widely used in foreign ordnance equipment. SBUV-IIT has been described in this paper. It is double proximity focused MCP (Micro-channel plate) image intensifier tube. It is 18mm active diameter of photocathode and phosphor screen. Input and output window is quartz glass and fiber optics faceplate respective. Photocathode material and phosphor screen is tellurium cesium compound and P20. It has been developed with a limiting UV resolution of 39 line pair per millimeter, and spectral response of 200~320 nm, photocathode maximum sensitivity of 29.5 milli-ampere per watt at wavelength 254 nm and a mass of 35g .It can be coupled with CCD easily. It has been well suited for fingerprint identify and camera system，It’ll be used for UV hail testing, UV earthquake forecasting and so on. Key Word: Ultra Violet light, Image intensifier tube, photocathode sensitivity, resolution.