Abstract: A thermionic heater cathode assembly for an electron-beam gun, comprising a disc cathode made of a highly-emissive material and disposed near a metal ribbon filament the thermionic portion whereof has a W shape, the distance between two apices of said thermionic portion being 0.6 to 0.8 of the disc cathode diameter and the depth of the valley between the apices constituting 0.5 to 0.6 of said diameter.

Abstract: Disclosure is made of a cathode assembly of an electron beam welding gun, comprising a current lead, wherein there is arranged a heating cathode which is coaxial with said current lead. Next to said heating cathode and coaxially with it, in a holder's sleeve there is arranged a disc cathode. The holder's sleeve is provided with a central orifice in its bottom to receive the disc cathode. On the internal surface of said sleeve, on the side opposite to the bottom, there is provided a cone-shaped recess widening towards the disc cathode, which recess receives a split ring of a refractory material, intended to press said disc cathode against the bottom of the holder's sleeve.

Abstract: A flat thermionic cathode is provided with a substrate having at least one main heating element thereon to produce at least one substantially localized area of heat and a sub-heating element to substantially define a heating area, the localized area being produced within the heating area. A cathode element including electron emissive material is disposed at the localized area. While the localized area tends to produce a temperature gradient directed from the localized area toward the perimeter of the substrate so as to create thermal stress in the substrate along the perimeter thereof, the sub-heating element reduces this temperature gradient and, consequently, the thermal stress.

Abstract: An electron emissive coating for long life fluorescent lamps comprises a composition of barium tantalate having the formula M(BaO) . N(Ta.sub.2 O.sub.5) where the ratio M/N is greater than 1.

Abstract: A reaction cathode with high thermic emission which is especially suited for vacuum tube application and which contains a compound of a monolayer forming element which is liberated by a supply reaction which proceeds during the operation of the cathode, wherein the monolayer forming element is at least one of the elements selected from the group consisting of yttrium and lanthanum, and wherein said cathode further contains at least one metal selected from the group consisting of palladium, platinum, rhodium and ruthenium, as a diffusion-enhancing agent.

Abstract: A fast warmup cathode comprises a substrate of nickel or cathode nickel alloy having an outer and an inner surface. At least an area of the outer surface is formed to receive an electron emissive material. The inner surface is provided with a high heat radiating material. The high heat radiating material comprises vacuum deposited aluminum or magnesium which has been fired at a temperature above the melting point of the material to provide a surface which is darker than the unaltered surface of the substrate.

Abstract: A dispenser cathode comprising a porous metal body which has an emissive surface and the pores of which contain one or more compounds for dispensing at least barium and scandium to the emissive surface, which compounds are composed of at least barium oxide, scandium oxide and aluminium oxide, in which the quantity of scandium oxide is less than 10% by weight, and preferably 3% by weight, of the overall quantity of the dispensing compound (s), has substantially the same good emissive properties as cathodes in which the dispensing compound comprises 5.5% by weight of scandium oxide and 18% by weight of yttrium oxide (Y.sub.2 O.sub.3), or barium scandate as a dispensing compound.

Abstract: An electron gun cathode for a cathode ray tube in which the cathode has a fast warm-up characteristic to produce a visible raster within about 6 seconds. The emissively-coated cathode cap is of reduced mass, with the cathode heater coil disposed within the cathode cap having a high weight to length ratio, and with a darkened coating thereon to increase the emissivity therefrom.

Abstract: A fast warm up, die-drawn, low mass cathode cap is substantially cup-shaped having a closed end and an upstanding side wall integral therewith. The thickness of the side wall is less than that of the closed end, permitting more of the heater energy to be concentrated in the closed end which carries, on the outer surface thereof, the electron emissive material.

Abstract: A multi-wire oxygen electrode and method of manufacturing the same, said electrode having a reactive electrode surface formed by a glass electrode tip having an end surface and a number of electrode wires are distributed in the end surface of the electrode tip along a circle. The cross-sectional surface of said electrode wires are freely exposed in such end surface and the electrode wires are fused in the electrode tip and electrically conductively connected with a cathode wire arranged in a glass sleeve. There is provided a substantially semi-spherical shaped support surface having an apex, said support surface being coaxially arranged with respect to the electrode tip, and said cathode wire being held in the electrode tip at the apex of the support surface.

Abstract: Performance of fast warm up cathodes can be improved by providing a black heat radiating surface on the interior of the cathode cap. A particular material can be nichrome which is a nickel chromium alloy. The cathode cap material can be selected from any of the known cathode nickel alloys. A preferred method for accomplishing the result includes the steps of cladding a selected nickel alloy with the nichrome material and then forming the substantially cup shaped cap with the clad material on the interior thereof. The formed cathode cap is then fired for about 10 minutes or longer in wet dissociated ammonia at a temperature of about 900.degree. to 1300.degree.C to oxidize the available chromium on the surface of the nichrome. This produces an even dark surface thereon which has much higher heat radiating capabilities than the silver looking nickel cathode alloy.

Abstract: A fast warm up cathode comprises a substantially cup-shaped top cap and a hollow cylindrical sleeve axially displaced from the top cap. Means are provided for joining the sleeve and the top cap into an integral unit. The means comprise a plurality of individual rod-like members having extremities substantially flat for attachment to the top cap and the sleeve. The plurality of rod-like members are equally spaced about the periphery of the sleeve and the top cap.

Abstract: A thermionic emitter for apparatus such as electron microscopes, scanning electron microscopes, and high power vacuum tubes which require a source of electrons formed from lanthanum strontium vanadate which is prepared from the compounds La.sub.(1.sub.-x) Sr.sub.(x) VO.sub.3, where x is the fraction of strontium (Sr) incorporated into LaVO.sub.3. The value of x lies between 0.1 and 0.4.