Method of estimating light loadings power and repetition frequency effects on the image quality of gated image intensifier tubes

摘要

Abstract: The photocathode surface resistance influence on the illuminance allowable level is studied both experimentally and analytically with due regard to the intensifier's photocathode unit design. Another subject of investigation is the effect of the repetition frequency of light pulses, commensurable in duration with gating voltage pulses of the shutter, on the tube spatial resolution. Experiments were staged using fabricated annular gate electrode image intensifiers. A novel design of the photocathode unit, the so-called capacitor substrata, has been proposed and tested in the tubes under investigation. Basing on theoretical analysis results, simplified equivalent electrical circuits are proposed. They enable a qualitative analysis of the photocathode unit to be easily performed. Also reported are experimentally obtained dependences of the critical allowable photocathode illuminance value upon the light pulse width as well as the relationship between the spatial resolution and the repetition frequency of such pulses for two versions of the photocathode unit design. The investigations demonstrated in particular that when the capacitor substrata is used, the critical allowable photocathode illuminance increases fourfold.!