RE-W cathode discharge properties in N2 and CO2 atmosphere at high temperature up to 1000 °C

Rare earth-tungsten (RE-W) cathode discharge properties in N2 and CO2 atmosphere at high temperatures were studied experimentally. The effect of temperature, atmosphere, cathode material and diameter on discharge current and corona inception voltage were investigated. The results show that the discharge current is larger and the corona inception voltage is lower in N2 atmosphere than in CO2 atmosphere. The range of the corona discharge voltage is narrower in CO2 atmosphere. When the temperature is above 900 °C, the corona discharge becomes very unstable. As the temperature increases, the discharge current increases obviously and the corona inception voltage decreases significantly. Besides, the discharge current increases and the corona inception voltage decreases with the decrease of cathode diameter. The corona inception voltage also decreases significantly with the decrease of work function of different cathodes.