摘要:
A thermionic emission cathode of a single crystal made of the calcium hexaboride type crystaline structure comprises a top surrounded by natural face inherent to the axial direction of the single crystal.
摘要:
An electron gun for high brightness including a LaB.sub.6 single crystal cathode having a (100) plane on at least part of a main electron beam emission surface of a cathode tip having a top and a Wehnelt having a tapered surface defining an interior angle similar to or greater than a vertical angle of said cathode tip.
摘要:
A thermionic emission cathode comprises a cathode tip made of an alkaline earth metal or rare earth metal hexaboride, a metallic support for supporting a base of said cathode tip and a reaction barrier layer comprising colloidal carbon and a reaction barrier material which bonds said cathode tip and said metallic support in one body.
摘要:
A method for manufacturing a thermionic cathode is provided which comprises cutting a bar from a multi-layer structure having a first layer of thermoelectron emissive compound and a third layer of metal of high melting point, a second layer of reaction barrier being interposed between said first and third layers, the bar being cut in a direction substantially perpendicular to that of the layers, sharpening the end of the first layer of the bar and then providing current terminals with the third layer of the bar. According to the method of the invention, a thermionic cathode capable of emitting stable electron beams of high intensity for a long period of time can be manufactured.
摘要:
A thermionic cathode for an electron beam device is provided which comprises a first layer of thermoelectron emissive compound sharpened towards a point, a third layer of metal of high melting point and a second layer of reaction barrier interposed between the first and third layers, current terminals being attached to said third layer. According to the invention, a thermionic cathode capable of emitting stable electron beams of high intensity for a long period of time can be manufactured.
摘要:
An evaporation vessel for vacuum evaporation of electroconductive ceramic boat for use in the vacuum evaporation of a metallic or non-metallic substance by virtue of resistance heating, wherein the surface of the adjoining portion on the both sides of a cavity is lower than the top of the outside wall of the cavity.
摘要:
A chlorosilane disproportionation catalyst comprising a tertiary amine of the formula: ##STR1## where each R represents an aliphatic hydrocarbon group and the sum of carbon atoms in the three aliphatic hydrocarbon groups as R is 12 or more, and a tertiary amine hydrochloride of the formula: ##STR2## where R is as defined above.
摘要:
A high temperature anticorrosive molded product produced by hot pressing a mixture comprising 1-10 weight parts of powdery aluminum and 100 weight parts of a powdery composition comprising an electric conductive refractory, boron nitride and aluminum nitride wherein said powdery composition is encompassed by the range electric conductive refractory : boron nitride : aluminum nitride as shown in the basal triangle of 40 : 20 : 40, 50 : 10 : 40, 70 : 10 : 20, 70 : 20 : 10 and 40 : 50 : 10 of FIG. 1.
摘要:
A thermionic cathode includes an electron emitting tip, lanthanum hexaboride tip supporting heaters in close contact with both sides of the tip and supporting the tip, and elastic electroconductive members in pressure contact with outer surfaces of the tip supporting heaters for supplying electric current. The tip supporting heaters are obtained by cutting lanthanum hexaboride having high anisotropy due to its layered structure so as to form a pair of parallel planes perpendicular to a pressing direction when hot-pressed, and abrade-polishing the parallel planes. The tip supporting heaters are brought into close contact with the tip and the elastic electroconductive members at the resulting smooth surfaces thereof. The apparatus of the invention has a prolonged lifetime and high efficiency.
摘要:
Metal is evaporated in a container which comprises an electrically conductive ceramic base whose surface in contact with the molten metal is coated with a film comprising, a main component selected from the group consisting of titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, niobium carbide, tantalum carbide, chromium carbide, molybdenum carbide, tungsten carbide, tungsten metal, tantalum metal and molybdenum metal.