Thermal balance in plane thermoionic cathodes of radio-frequency tubes without anodes

Cathode units of high power radio-frequency tubes are conventionally used in electron injectors with high repetition rate. This cathode utilization results in disturbance of the temperature regime of the cathode surface because of cutting the anode, which is “thermal mirror” in the tube. Estimations made in this work show an essential lowering of the emitter temperature for both porous metal and oxide cathodes without anodes. It shows that the oxide cathode utilization results in a significant thermal gradient in the oxide layer.