Abstract: A direct heating thermionic emission cathode for high frequency tubes of the diode, tetrode or pentode type. It comprises a pyrolytic graphite support and a lanthanum hexaboride-based thermoemissive material, these elements being separated by a layer which constitutes a diffusion barrier and comprises a tantalum or hafnium carbide, a metal of the platinum group or a boron compound.

Abstract: This heating element is constituted by a filament and a mixture, fritted at between 1700.degree. and 1800.degree. C., of alumina and less than 10% by weight of yttrium oxide. This mixture fills the space left free by the filament within the cylinder closed by an emissive disk forming the cathode.

Abstract: A method is disclosed to fabricate a cathode electrode for a continuous wave magnetron so that the resulting product is relatively free from random frequency modulation and frequency "pushing". The method generally comprises the steps of forming, from a slurry containing comminuted tungsten and thorium hydride, a cathode electrode of the desired shape and heat treating such cathode to remove all volatile elements and ultimately to form a cathode electrode made up of an eutectic mixture of tungsten and thorium particles of tungsten.

Abstract: Photocathode of SbK.sub.2 Cs destined for any electro-optical tube.Photocathode (11) comprising a layer (12) of potassium and caesium antimonide SbK.sub.2 Cs deposited on the substrate (13), also comprising a sub-layer (14) of manganese oxide, intermediate between the said substrate (13) and the said layer (12) of SbK.sub.2 Cs, the said sub-layer (14) of MnO improving in the red the spectral sensitivity of the layer (12) of SbK.sub.2 Cs.Application notably for photomultiplier tubes used in nuclear physics.

Abstract: A thermionic cathode (FIG. 1) comprises a porous matrix of tungsten (4) impregnated with alkaline earth activator.A coating (5) 1 .mu.m thick is formed on the matrix (4). The coating is of .sigma. phase alloy of molybdenum and osmium.Alternative .sigma. phase alloys are disclosed, and various methods of making cathodes are disclosed.

Abstract: An electric discharge type device is described having electrode means which include a refractory metal substrate having sintered thereon an open porous coating of refractory metal particles at a thickness up to about 1 millimeter thickness with electron emissive material being disposed in the pores of said sintered refractory metal coating. Representative electric discharge devices having said improved electrode means include discharge type electric lamps and photographic flash tubes wherein the electrode members have an elongated shaped body which is terminated at one end to provide more surface area for the coatings sintered thereon. Various electron emissive materials can be employed for impregnation of the open porous coating of refractory metal particles by such conventional techniques as dipping or spraying.

Abstract: A variety of technologies have been applied in the development of a bonded rid cathode. Erosion lithography is used for making the fine-detail grid structure, combining air erosion and lithographic techniques. To obtain openings of the order of 0.001 inch (one mil) or smaller, a nozzle with a high aspect ratio exit opening is used, and the cathode grid structure is scanned. A photo resist in which the grid pattern is developed is used over the molybdenum or tungsten grid film. The metal film is removed from the grid openings by chemical etching. The photo resist over the metal grid is used as a composite mask for removing the BN insulation in the openings by erosion with Al.sub.2 O.sub.3 powder from the special nozzle on the air blast gun.

Abstract: Cathode structures for cathode ray tubes are multi-layer structures wherein the bond between the emissive coating and the substrate is improved by forming the coating from a laminate of at least two self-supporting layers of differing compositions, the bottom layer optimized for bonding to the substrate and the top layer optimized for emissive properties.

Abstract: Cathode structures for cathode ray tubes are multilayer structures wherein the multilayer structures are formed from a laminate of at least two self-supporting layers of particles of emissive material dispersed in a fugitive organic binder matrix.

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 plasma display panel with an electrode composed of a metal layer (e.g., Fe and Ni) and a metal compound layer (e.g., alkaline earth metal oxide or sulfide, and rare earth metal hexaborides) which are formed by means of plasma spray coating. The plasma spray coating should be done at such a temperature that the metal or metal compound is in the molten state.

Abstract: The hot cathode, according to the invention, is constituted by a fritted matrix 1 and a heating filament 4, said matrix being formed from a powder mixture 2 of tungsten and another high work function refractory metal and covered with a high work function refractory metal film 3. FIG. 3.

Abstract: A one-piece, directly heated cathode is disclosed for use in a cathode ray tube electron gun. The cathode according to the invention has the configuration of a hollow cylinder with one closed end for receiving a thermionic electron-emissive coating. A pair of body portions extending axially in the same direction from diametrically opposed sides of the closed end define two legs which act as serial electrical conductors having inherent resistance for use in resistively heating the electron-emissive coating. The legs have an arcuate cross-section effective to structurally stabilize the cathode and suppress temperature-induced lateral displacement of the cathode which would otherwise degrade the performance of the electron gun.

Abstract: A directly heated type oxide cathode comprising a base made of an alloy containing Ni as a major component and Zr as a reducing agent, a diffusion prevention layer made of Co formed on the base, a coating of Ni powders formed on the diffusion prevention layer, and an electron emissive alkaline earth oxide layer formed on the coating of Ni powders, does not show deformation of Ni powders or peeling of the oxide layer during the production procedures or operation of the cathode.

Abstract: A controlled porosity sheet defining a surface for a thermionic dispenser thode and a method of manufacture. Starting with a generally flat silicon template substrate structure having an array of upstanding microposts 1-25 microns across on 5-100 micron spacings from each other, a layer of metal is deposited on the substrate to surround the microposts and cover the substrate structure to a desired depth. The metal layer is then abraded to a smooth, flat surface which exposes the microposts. Thereafter, the silicon substrate and microposts are completely etched away, leaving a metal sheet having micron-size holes therethrough.

Abstract: A field emission cathode of the present invention is characterized by the possession of a special layer which is adsorbed onto the surfaces of a tip that is joined to the top of a hairpin-shaped filament.This layer is formed by adsorbing a selected metal via oxygen to a thickness which does not exceed the thickness of the monolayer of atoms.The metal will be selected from chromium, aluminum, cerium, magnesium, titanium, silicon, zirconium or hafnium.The field emission cathode features that the electrons are emitted in a concentrated manner from a particular crystal plane among the crystal planes of the tip.Therefore, it is possible to obtain a field emission cathode having very small emission angle of electrons.

Abstract: An oxide-coated cathode used for the electron tubes such as cathode ray tubes and camera tubes, comprising as the base a sintered product principally composed of an alkaline earth metal compound and a high-melting-point metal and having high heat conductivity and low specific resistance, said sintered product being either used singly or layered on a high-melting-point metal body containing a reducible element or elements as impurity, and an oxide cathode material coated on said base, and a method of producing such oxide-coated cathode.

Abstract: An electron gun having a cathode of a lanthanum hexaboride single crystal is disclosed in which the axis of the cathode is set to such a crystal orientation that the electron beam has two intensive emission regions which are asymmetrical with each other in intensity. In the electron gun, even at a low heating temperature of the cathode, a single spot of an image by the electron beam of a more intensive emission region since the electron beam of a weaker intensity emission region is blocked by an aperture.

Abstract: An electrode activating compound for a gas discharge tube such as a surge voltage arrester, triggerable gas discharge tubes and flash tubes in which a titanium oxide is used in place of the radioactive thorium oxide. Preferably, the titanium oxide is provided by a reduction of a titanium dioxide with a reducing agent such as BaAl.sub.4 or metallic titanium or by oxidation of a titanium hydride in either an oxidizing atmosphere or with an oxidizing compound.

Abstract: A compressed dispenser cathode having 1-15% by weight of Ba.sub.2 Sc.sub.2 O.sub.5 in a porous metal cathode body has an emission having a larger current density (exceeding 6 A/cm.sup.2) and a longer life (more than 3000 hours).

Abstract: A directly heated cathode for electron tube having a stable electron emission characteristic is provided. The cathode comprises a base metal of Ni-W alloy consisting essentially of 20-30% by weight of tungsten, the balance being nickel and incidental impurities, said alloy being free from a reducing agent, and a layer of thermoelectron emission oxides laid directly and baked onto the flat part at the front side of the base metal. The layer of thermoelectron emission oxides is in direct contact with the flat part of the base metal.

Abstract: An electron gun for a shaped beam type electron beam delineating system is provided with a cathode which is prepared from a single crystal of lanthanum hexaboride (LaB.sub.6) the convex end portion of which has a tip radius ranging between 260 and 1,000 microns. The electron gun of the invention has a long effective life for producing a stable electron beam which can irradiate a limiting aperture with a uniform current density and insures the sufficiently high brightness of the electron beam image projected on a target.

Abstract: The invention relates to a semiconductor cathode based on avalanche breakdown in the p-n junction. The released electrons obtain extra accelerating energy by means of an electrode provided on the device. The achieved efficiency increase makes the manufacture of such cathodes in planar silicon technology sensible. Such cathodes are applied, for example, in cathode ray tube, flat displays, pick-up tubes and electron lithography.

Abstract: Disclosed is an electron-beam cathode which emits electrons with a low work function over a relatively wide range of temperature and pressure. The cathode is comprised of single crystal tungsten having zirconium and oxygen dopant atoms within the bulk thereof. This cathode is formed by the steps of attaching zirconium to a portion of the surface of single crystal tungsten, and heating the tungsten with the zirconium attached thereto in an atmosphere of oxygen to diffuse the zirconium and the oxygen into the bulk of the tungsten.

Abstract: Disclosed is an electron-beam cathode which emits electrons in a cone-shaped pattern whose electron density is substantially uniform throughout the cone. The cathode is comprised of a needle-shaped piece of single crystal tungsten having dopant atoms of zirconium and oxygen in the bulk thereof, and having only a single (100) surface on the needle's tip. This cathode is formed by the steps providing a needle-shaped piece of single crystal tungsten having dopant atoms of zirconium and oxygen in the bulk thereof, and having a plurality of ring-shaped (100) surfaces on the needle's tip; and subsequently transforming those surfaces into diagonally oriented planar surfaces by heating the needle in an atmosphere of oxygen to diffuse tungsten atoms from the needle's tip to its sides.

Abstract: High-pressure sodium vapor discharge lamps are used which contain an electron-emitting material consisting of alkaline earth metal bound to oxygen and tungsten bound to oxygen. It has been found that such lamps which have a high Hg/Na ratio, use neon/argon as a starter gas or have powers of less than 400 W fail prematurely when the alkaline earth metal and tungsten in the electron-emitting material are present in stoichiometric quantities (total alkaline earth metal oxide: WO.sub.3 =3).The free ends of electrodes of lamps according to the invention are wound with tungsten wire. Electron-emitting material consisting of strontium bound to oxygen and tungsten bound to oxygen is disposed in the cavities formed between the tungsten wire turns. The molar ratio of the strontium bound to oxygen to the tungsten bound to oxygen is between 3 and 50.

Abstract: An electrode for a discharge lamp such as high pressure metal vapor lamps and fluorescent lamps is improved by using an electron emission material comprising lanthanum oxide and yttrium oxide. The electron emission material can be a combination of lanthanum oxide and yttrium oxide with barium.strontium.calcium tungstate or an alkaline earth metal oxide including at least barium oxide.When the electrode is used in a high pressure metal vapor discharge lamp, luminous flux maintenance percent in an initial lightening period is highly improved without forming a black deposition at an end of an arc tube.When the electrode is used in a fluorescent lamp, a formation of a black deposition is prevented and a starting voltage is lowered.

Abstract: An oxide-coated cathode for electron tubes comprising a base metal plate made of an alloy containing nickel as a major component and at least one high-melting point metal in an amount of 2% by weight or more, and if required, a small amount of one or more reducing elements, and an electron emissive alkaline earth metal oxide layer adhered to the base metal plate, characterized by having a carbide layer made of at least one carbide of Si, B, Ti, Zr, Hf, V, Nb, Ta, Mo or W between the base metal plate and the electron emissive alkaline earth metal oxide layer can maintain electron emitting life for a long period of time due to the prevention of interfacial reaction between the base metal layer and the alkaline earth metal oxide layer.

Abstract: A dispenser cathode is fabricated by covering a reservoir of electron emitting material with a perforated metal foil having an appropriate pattern of pore-sized apertures thereon for providing uniform electron emission from the cathode surface. The electron emitting material is in the form of a pellet of barium oxide impregnated with a wax or resinous material to minimize chemical reduction of the barium oxide in air. The impregnated barium oxide pellet is sandwiched between the apertured foil and a support structure to which the foil is welded. During tube bake-out or subsequently during cathode activation, the wax or resinous material evaporates and barium oxide migrates through the apertures to cover the surface of the foil in a uniform manner. The desired pattern of apertures in the foil is achieved by photolithography, or by forming the foil (e.g., by chemical vapor deposition, sputter deposition, evaporation, or sintering) on a substrate containing an array of protruding posts.

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: In an exemplary embodiment, a metal capillary cathode for electric discharge vessels with an emission substance carrier disk porous on its front face and comprised of metal melting at a high temperature is constructed to prevent lateral emission of electrons (interfering emission). To this end, the disclosure provides that the emission substance carrier disk has a nonporous outer casing surface with a higher electron work function than the outer, active surface of the emission substance carrier disk. Such a dispenser cathode is employed as a metal capillary cathode in traveling wave tubes.

Abstract: Emission quantity of thermionic cathodes is increased by including in the potentially emissive material applied to a cathode substrate a quantity of a readily reducible metallic oxide. During cathode processing the metal oxide provides free oxygen gas which aids in binder removal.

Abstract: A sintered electrode in a discharge tube comprises a sintered compact body and a cesium compound layer deposited on the sintered compact body. The sintered compact body comprises a gas getter such as titanium in the range of 5 to 50% by weight of the body, an additive for sintering such as silicon oxide in the range 0.1 to 1.0% by weight of the body and the remainder formed by a high melting point metal such as tantalum.

Abstract: In a discharge lamp comprising a sintered electrode comprising a high temperature melting metal such as tungsten, molybdenum, tantalum or mixtures thereof as a main ingredient of the sintered electrode and an electron emissive material of an alkaline earth metal or compound thereof, the sintered electrode further comprising at least one oxide of a metal selected from the group consisting of yttrium, zirconium and aluminum.

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: 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.

Abstract: A method of making transmission mode glass-sealed negative electron affinity (NEA) gallium arsenide (GaAs) photocathodes, utilizing germanium (Ge) as the seed crystal and multilayers of GaAs and gallium aluminum arsenide (GaAlAs) grown by metal alkyl-hydride vapor-phase epitaxy. The GaAs serves as the photoemitting layer and the GaAlAs serves as the passivating layer. The Ge, GaAs,GaAlAs combination is sealed to a glass support substrate which serves as the input window for the device. Finally, the Ge is removed and the GaAs is activated.

Abstract: A thermionic emission cathode comprising a base metal made of nickel-tungsten series alloy, for example an alloy comprising 90 to 70% by weight of nickel and 10 to 30% by weight of tungsten, and an emitter layer, which is formed on the base, made from a mixture of (a) tungsten powder or nickel-tungsten alloy powder comprising 90 to 70% by weight of nickel and 10 to 30% by weight of tungsten, (b) Ba.sub.3 WO.sub.6 powder and (c) zirconium powder or ZrH.sub.2 powder, and if necessary interposing a powder layer between the base and the emitter layer, said powder layer having the same composition as the base metal and a particle size of 1 to 10 .mu.m sealed on the surface of the base with a distribution density of 0.5 to 5.0 mg/cm.sup.2, can be applied to both directly and indirectly heated type cathodes. Said cathode has such advantages as being able to be miniaturized and to have high current density.

Abstract: A hot-cathode material in wire or sheet form, comprising a high-melting carrier metal, an oxide activator and a carbide reducing agent, and, optionally, a diffusion-promoting additive, the material comprising a core zone and at least one surface layer having different compositions or different concentrations of constituents therein which are such that, in operation, the rate of diffusion of the activator from the core zone is equal to or greater than the loss of activator from the surface layer. The material is made by a powder metallurgy/thermo-mechanical process.

Abstract: A discharge type electric lamp construction is described having electrode means which include a porous sintered body of refractory metal having an electron emissive material containing cesium ion dispersed in the pores of said porous sintered body as Cs.sub.2 MO.sub.4 wherein M is a refractory metal. Said electron emissive material is preferably employed in combination with another electron emissive material containing barium ions to provide a lower breakdown voltage as well as operating voltage characteristics for said discharge lamps. Representative electron emissive materials containing barium ions include barium aluminate and barium tungstate materials.

Abstract: A reaction thermionic cathode of the diffusion type on the basis of an activated high-temperature support metal doped with a diffusion-promoting additive for the activator substance, provided with a barrier layer inhibiting the self-diffusion of this additive in an undesired direction.

Abstract: An oxide cathode wherein a base is made of an alloy comprising Ni as a main component and at least one reducing element selected from the group consisting of Mg, W, Zr, Si, Al and C, and the surface of the base is coated with an alkaline earth oxide layer containing at least BaO, the BaO content in the inner portion of the oxide layer contacting with the base being lower than that in the superficial portion of the oxide layer, if desired, forming a roughened layer made of powdered Ni or the like between the base and the inner portion of the oxide layer, can inhibit the formation of interface layer of, e.g. Ba.sub.3 WO.sub.6 and maintain stable thermion emitting characteristics for a long period of time.

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.

Abstract: An aluminum flux method of preparing binary, ternary, and quaternary single crystal metal hexaborides. The single crystals are prepared by mixing a metal oxide, carbonate, or nitrate compound with boron powder in an amount of aluminum which will solubilize the boron at a reaction temperature of from about 1200.degree. C. to about 1600.degree. C. The mixture is held at the reaction temperature for a sufficient time to form the desired single crystal hexaboride.

Abstract: A cathode assembly for electron emission, comprises, a heatable support of high-temperature resistant material, an emitter body of lanthanum hexaboride, and an auxiliary body having a surface contact with both the support and the emitter body, which is made of a third material, comprising a sintered material of the class of carbides, nitrides and borides. The surface contact area between the auxiliary body and the support amounts to at least 1/6 of the surface area of the emitter body.

Abstract: A light source is disclosed which can be used in atomic absorption analysis using the Zeeman effect. In operation, an external magnetic field is applied to the hollow cathode of the light source to cause the Zeeman-splitting of an emission line from the cathode material. The hollow cathode is made of a ferromagnetic metal as which is the element of interest for analysis and a metal for reducing the magnetic shield of the externally applied magnetic field by the ferromagnetic metal so that the external magnetic field effectively acts on the hollow portion of the cathode to provide the desired Zeeman-splitting. The hollow cathode is designed such that the product of the saturation flux densities of the cathode materials and the volume thereof is equal to or smaller than 0.2(Wb.multidot.m).times.10.sup.-6. The emission line from the cathode material is produced by excitation from a high frequency power supply, the power supply being connected to the cathode and the anode of the light source.

Abstract: An arc discharge lamp electrode is coated by applying thereto a suspension of alkaline earth compounds in a liquid vehicle of lignosulfonic acid, ammonia and ethylene glycol.

Abstract: Cathodes having a support for emissive material of foamed carbon are mechanically stable and resistant to detrition and have a homogeneous pore distribution.

Abstract: Disclosed is a gas-discharge display panel having plural discharge cells arranged in a matrix. Each of the discharge cells is provided with a hot cathode consisting of conductive material having a shape which provides a heat capacity and heat conductivity as small as possible. Each cathode is coated by an electron emissive material having a small work function. As a result, the hot cathode can be heated to a required working temperature solely by the bombardment of particles contained in a discharge current itself, without requiring any externally supplied heating power to obtain a highly efficient use of applied driving power.

Abstract: In a high pressure electric discharge lamp having tungsten electrodes and a discharge envelope filling of mercury, rare gas, and metal halides, activator material consisting essentially of scandium oxide is incorporated in the electrodes, in the form of a solidified melt substantially filling a cavity in the electrode and adherent to the electrode structure, and the halides of the filling consist of iodide(s) and bromide(s), including scandium iodide and/or scandium bromide, in relative proportions such that the atomic ratio of total bromine to total iodine is 20:80 to 60:40. The electrodes are preferably tungsten wire coils, the scandium oxide filling the interior of the coil and penetrating into the interstices between the coil turns. The filling preferably includes sodium iodide and/or sodium bromide, and may include additional iodides and/or bromides. The combination of the scandium oxide activator and the bromide/iodide filling gives high luminous efficacy and good lumen maintenance.