Abstract: The present invention relates to an impregnated cathode produced by attaching at least two layered thin films, the thin films comprising an under layer consisting of a high melting point metal thin film composed of, for example, Os, Ru, Rh, Pd, Ir, Pt, Re, Mo, W, Ta, etc., and an over layer consisting of a high melting point metal layer which contains Sc.sub.2 O.sub.3 and which is placed over the layer, on the surface of the impregnated cathode pellet generated by impregnating a refractory porous base body with electron emissive materials. The invention relates also to an electron tube having this cathode. This cathode maintains a low work functional mono-layer stably for a long period of time on its surface.

Abstract: A gas discharge display panel adapted for effecting display by a plurality of gas discharge elements arranged in a matrix has a cathode formed by coating the substrate surface with a (100) preferred film of a rare earth hexaboride such as LaB.sub.6. The gas discharge display panel can be driven at relatively low voltage.

Abstract: An impregnated cathode comprising a refractory porous body impregnated with an electron emissive material and having an electron emissive surface, and a thin film disposed on the electron emissive surface and composed of a refractory metal and one of Sc, scandium oxide and a mixture thereof. The thin film containing Sc or scandium oxide is generated on the body in subsequent to impregnation of the electron emissive material into the refractory porous body with the result that a mono-atomic layer composed of Ba, Sc and O is maintained on the electron emissive surface over a long period of use.

Abstract: A liquid metal ion source for emitting P ions, wherein a Cu alloy which contains at most 25 at. % of P and if necessary, further contains Ag, C or Si, and/or B is melted and fed to an emitter tip so as to generate an ion beam under a high electric field.

Abstract: An impregnated cathode comprises a porous refractory substrate of refractory material such as tungsten containing at least one of scandium oxide particles and oxide particles containing scandium such as (Al, Sc).sub.2 O.sub.3, and an electron emissive material impregnated into pores of the substrate, and has an operating temperature lower by about 300.degree. C. than that of the conventional impregnated cathode containing no scandium oxide particles, or scandium.

Abstract: An impregnated cathode having a complex porous body of one-body construction which is mounted in a metal sleeve and in which a partition layer made of a porous material having a porosity less than 17% is arranged in close contact with an impregnated layer made of a porous material containing an electron emissive material. The aforementioned porous partition layer takes the place of the conventional partition plate of refractory metal. The impregnated cathode according to the present invention can not only have its size reduced without any difficulty but also enjoy a high emission current density with a remarkably small dispersion.

Abstract: A directly heated cathode for an electron tube comprising a base plate made of an alloy containing 20 to 30% by weight of W, 0.12 to 0.28% by weight of Zr and the remainder being Ni and an electron emissive oxide layer disposed directly on the base plate shows good and stable electron emission properties and when it is installed in a television picture tube, the picture tube shows excellent initial properties.

Abstract: An electron tube cathode has a composite suppression layer structure interposed between the base metal and the electron-emitting material to suppress an interface layer formed through the reaction of the base metal with the electron emissive material. The composite layer structure includes a thin layer of Pt or Re and a layer of oxide of Zr and/or Hf. As a result, the formation of the interface layer is prevented so that the useful life of the electron tube cathode is prolonged.

Abstract: An electron tube cathode in such a structure comprising a Ni-W-Zr alloy (W content: 20-28 wt. %) having a grain size of 4-10 .mu.m as a base metal, a 1,000-2,000 A-thick Pt film provided on the surface of the base metal, and an electron emitting material layer consisting of alkaline earth metal oxide provided on the Pt film has less emission lowering and less peeling of the electron emitting material layer, even if placed in a long time service. The electron tube cathode can be produced according to a method comprising (i) a step of annealing a base metal of Ni-W-Zr alloy (W content: 20-28 wt. %) at 1,000.degree.-1,200.degree. C., (ii) a step of providing a 1,000-2,000 A thick Pt film on the surface of the base metal, and (iii) a step of providing an electron emitting material layer consisting of alkaline earth metal oxide on the Pt film.