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 Y
2
Hf
2
O
7
Ceramic cathode had been developed. The thermionic emission and lifetime characteristics of the Y
2
Hf
2
O
7
cathode had been measured. The results show that the cathode can provide 0.15A/cm
²
, 3.5A/cm
²
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/cm
²
at 1400Cbr.