Stability of transmission-mode GaAs photocathodes in an ultrahigh vacuum system

In order to explore the stability of transmissive GaAs photocathode in ultra-high vacuum system, the activation experiment and re-caesiation experiment of transmissive GaAs photocathode were carried out, and the photocurrent curves after CsO activation and after re-caesiation were tested. Experiments show that high and low temperature thermal cleaning is conducive to CsO deposition and forms a stable structure to improve the photoelectric emission capability and stability of the transmissive GaAs photocathode. Although re-caesiation activation can partially restore the photoemission efficiency of the transmissive GaAs photocathode, it will reduce the stability of the activation layer and shorten the lifetime of the transmissive GaAs photocathode.