Method of manufacturing a scandate dispenser cathode and dispenser cathode manufactured by means of the method

Abstract

A method of manufacturing a scandate dispenser cathode having a matrix at least the top layer of which at the surface consists substantially of tungsten (W) and scandium oxide (Sc.sub.2 O.sub.3) and with emitter material in or below said matrix. If said method comprises the following steps: (a) compressing a porous plug of tungsten powder (b) heating said plug in a non-reactive atmosphere and in contact with scandium to above the melting temperature of scandium, (c) cooling the plug in a hydrogen (H.sub.2) atmosphere (d) pulverizing the plug to fragments (e) heating said fragments to approximately 800.degree. C. and firing them at this temperature for a few to a few tens of minutes in a hydrogen atmosphere and slowly cooling in said hydrogen atmosphere (f) grinding the fragments to scandium hydride-tungsten powder (ScH.sub.2 /W) (g) compressing a matrix or a top layer on a matrix of pure tungsten from said ScH.sub.2 /W powder or from a mixture of this powder with tungsten powder (h) sintering and cooling the said matrix (i) bringing emissive material into the cathode, a scandate dispenser cathode is obtained the recovery of which after ion bombardment occurs better than in cathodes having Sc.sub.2 O.sub.3 grains. The scandium is also distributed more homogeneously in the cathode than in cathodes having Sc.sub.2 O.sub.3 grains.

Dependencies are inferred from the claim text.