METHOD OF MAKING DISPENSER CATHODE Russian patent published in 2008 - IPC H01J9/04 

FIELD: electrical engineering.

SUBSTANCE: invention pertains to electronics, and specifically to methods of making dispenser cathodes for vacuum tube devices. The method involves pressing-in powder of refractory metal into a cup made from molybdenum and treatment at 1700-1800°C in hydrogen formed by porous sponge of active material in form of aluminate or arium-calcium aluminosilicate with subsequent removal of the active substance from the surface of the cup and sponge and formation of an emitting surface of the cathode. Tungsten powder is pressed into a cup made from molybdenum. The cup with the sponge is put into a container made from molybdenum, it is filled with powder of active substance which is heated until melting state and the sponge is impregnated under conditions of complete coating by the melt of the cup with the sponge. After cooling to room temperature, the container is put in water, and kept there until formation of a layer of jelly-like mass in the region of contact of the water and the melt of the active substance, which is washed by a stream of water. The operations described above are repeated several times until the active substance is completely removed from the surface of the cup and sponge. The cup with the sponge is dried in air, stock is removed from the sponge and the emitting surface of the cathode is formed.

EFFECT: simplification and increased accuracy of making the cathode, easement of the conditions of storing semi-manufactured cathodes.

4 cl