Thermionic Emission of a Novel Y2Hf2O7 Ceramic Cathode Applied in High-Power Magnetron Tubes

In order to enhance output power and prolong lifetime of the high-power magnetron tubes, a novel Y2 Hf2 O7 Ceramic cathode had been developed. The thermionic emission and lifetime characteristics of the Y2 Hf2 O7 cathode had been measured. The results show that the cathode can provide 0.15A/cm², 3.5A/cm² current density for the space charge limitation at 1300 Cbr, 1600 °C br respectively under 300V anode voltage. The lifetime of the cathode is more than 4100 h with an initial load of 0.5A/cm² at 1400Cbr.