Simulation of yttria hot cathode and radiative emissivity impact on its performances and the work function measurement

—Despite the decline in their use after the advent of semiconductor devices, hot cathodes still find applications in specialized detectors and high-power systems. This paper focuses on the simulation of the thermal behavior of an oxide cathode (Y₂O₃), considering the variation in emissivity as a function of both material and temperature. Most previous studies on hot cathodes have overlooked the importance of radiative emissivity, a parameter that significantly affects thermal exchange, electronic emission and hence the measurement of the work function with a Richardson plot. Our results emphasize the need for a precise measurement of material emissivity to accurately assess cathode performance and enable fair comparisons between different cathode types.