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AssigneeU.S. Philips Corporation
InventorsJacobus A. J. M. Deckers, Theodorus H. Weekers, Albert Manenschijn, Franciscus M. M. Snijkers, Petrus A. M. Van Der Heide
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A method of manufacturing a dispenser cathode, in which method a powder of a refractory metal and a scandium-containing powder are mixed with each other and pressed to form a cathode body. According to the invention at least both these powders and a suitable binder are mixed with each other to form a homogeneous suspension prior to the pressing operation and the whole mixture is subsequently cured and ground to granules having a larger average size and hence a greater fluidity than the grains of the starting powders. Subsequently the granules thus obtained are pressed to form a cathode body (2). The invention leads to a better processibility and greater convenience of handling of the starting powders so that notably very fine starting powders can be used, which results in cathodes (1) having a better recovery after ion bombardment as compared with cathodes manufactured in conventional manners which are necessarily based on relatively coarse powders.
A dispenser cathode having a cathode body within a holder, the cathode body comprising a refractory metal, a rare earth metal-containing material and electron emissive material characterized in that the entire cathode body within said holder is obtained by pressing a mixture comprising grains of the refractory metal, grains of the rare earth metal-containing material and a pulverulent barium containing material and sintering the resultant pressed mixture, the grain size of the majority of grains of the refractory metal being smaller than 5 .mu.m and the grains of the rare earth metal-containing material having an average grain size of less than 10.mu..
Dependencies are inferred from the claim text.