Effect of residual gas on cathode photoelectric emission life in generation III L-L-L tube

In order to solve the sensitivity’s degression in the GaAs NEA photocathode, our crew dissected the Gen. III Low-Light-Level（L-L-L）tube and analyzed the residual gas from the tub e while functionally operating via mass spectrometer. The photoemission-harmful gas like C，CO，CO2 were the principal reason cause the photocathode sensitivity to drop most. Applying the theory of dipole layer, this paper had this thorough discussion over the impact the residual pernicious gas had upon the photocathode. The residual gas on the emission layer enlarged the interface barrier and dwindled the chance of overflow about the same time.There were none photoemission when the single molecule gas were all over the emission layer, and so the life-span has came to an end as well. Our crew bring forward “carbon-contamination precaution measure” on account of lo wering potential barrier, which resolve problems like unstable photocathode sensitivity and limited life-span.