Automatic recording system of dynamic spectral response and its applications

Spectral response curves of photoemission materials and spectral matching factors between detectors and reflecting spectrum of scenes are of importance in the study of detectors and imaging devices. For studying the two questions an automatic spectral recording system was developed and the schematic diagram of the system was demonstrated in this paper. A lot of experiments by use of the system were made to obtain spectral response curves and characteristic parameters of multi-alkali and GaAs:Cs-O photocathodes during activation procedure and these experimental results were given. It was found that electron affinity of Na2KSb, Na2KSb+Cs and [Na2KSb+Cs]+Sb+Cs multi-alkali photocathodes were 0.70-0.91eV, 0.35-0.41eV and 0.33eV respectively calculated from threshold wavelength of spectral response curves and quantum yield during preparation. On-line spectral response measurements of GaAs:Cs-O reflection-mode photocathodes during activation process and decay procedure were carried. The prepared GaAs:Cs-O reflection-mode photocathodes which used national p-type GaAs substrate can obtain 1025μA/lm sensitivity.