The study of channeled vacuum GaAs photocathodes for enhanced electron emission properties

In this paper, we design and analyze the channeled vacuum photocathodes with novel structures towards low operating temperature, high current density, and miniaturized cathode electron sources. We simulate the characteristics of the electron emission of the channeled vacuum GaAs photocathodes in detail with the commercial CST software. Simulation results indicate that the emission current of the photocathode can increase with the optimal gate and anode voltage choices, and the emission efficiency can reach up to 63.4 %. Using this optimized structure as the benchmark, the quantum efficiency and emission efficiency are also investigated. Furthermore, we have altered the channel morphology, i.e., with the curved vacuum channel structures, to enhance the current density. We have found that the emission current density can increase significantly and reach up to 2.68 times of the regular rectangular channel. The simulation results can lay the foundation for the development of new type of micro-structured GaAs photocathodes.