METHOD OF MAKING DISPENSER CATHODE Russian patent published in 2014 - IPC H01J9/04 

FIELD: electricity.

SUBSTANCE: method of making a dispenser cathode includes pressing tungsten powder at pressure P=8-15 t/cm² into a cup made by grinding a molybdenum bar, with an inner height sufficient to form therein a porous sponge which is saturated with an active substance at temperature t=1700-1800°C in a hydrogen medium, after which excess active substance is removed, the surplus is ground down and an emitting surface is formed. Before pressing, an admixture of nanopowder of amorphous ultrafine silicon oxide SiO₂ is added to the tungsten powder in amount of 0.01-0.08% of the weight of the tungsten powder, and the obtained mixture is then annealed in a hydrogen medium at temperature t=1600-1800°C for 5-30 minutes.

EFFECT: making large-size cathodes with an irregularly shaped emitting surface, longer service life by generating a lamellar electron stream with minimum fluctuations, minimum allowable deposition of electrons in the flight channel, absence of local overheating of the collector and absence of return ions and electrons.

2 cl, 1 tbl