New development in plasma-sprayed oxide cathode research

In order to improve the mobility of feed material and to generate a coating conducive to electron emission, the author is attempting to employ co- precipitation method to prepare ball-shaped (Ba,Sr,Ca)CO
3
. The experimental results show that the carbonates has sound mobility and has been successfully used as feed material in plasma spraying process to prepare oxide cathode. The experimental results also show that the pulsed-current emission density of the cathode is 40.5A/cm
²
with a 5-μs pulsewidth and a 200 Hz repetition frequency at 850 °С, whereas that of the plasma-sprayed oxide cathode prepared by using sintered carbonates is 31.6 A/cm
²
with a 1-µs pulsewidth and a 100 Hz repetition frequency at 850 °С.