Abstract: An electron emitting device, comprising: a first electrode provided on a substrate; a first layer provided on said electrode and capable of undergoing transition from an electrically high resistance state to a low resistance state when irradiated by a radiant ray; and a conductive layer, an insulating layer and a second electrode, laminated on said first layer. An electron generator includes the electron emitting device as well as an applicator for applying an electric field to said device, and an irradiator for irradiating a radiant ray on the device. A method for driving the electron emitting device is also provided.

Abstract: For the purpose of generating an electron beam (5), a quasi-optical gyrotron comprises an electron-beam gun (1) with an annular cathode (2). The electron beam (5) passes along an electron beam axis (6) and in so doing is compressed by a static magnetic field and forced into gyration, so that it excites in a quasi-optical resonator a standing alternating electromagnetic field of specific wavelength. The resonator exhibits two mirrors (9a, 9b) arranged opposite to one another on a resonator axis (8) aligned perpendicular to the electron beam axis (6). In order to increase the efficiency of the gyrotron, the annular cathode (2) alternately exhibits segments of high and low emitting power such that the electron beam (5) has an azimuthally varying current density, values of low current density in the resonator coinciding spatially with nodal surfaces of the standing alternating electromagnetic field.

Abstract: A cathode for use in electron tubes which comprises a base metal made of nickel as a principal component and having a surface on which a porous electron emissive layer is formed. The porous electron emissive layer is of a composition comprising 0.1 to 20 wt % (relative to the total weight of the porous electron emissive layer) of scandium oxide having a layered crystalline structure dispersed in an oxide of alkaline earth metal including at least barium. This cathode can be made by preparing a solution in which nitrocellulose is dissolved with the use of an organic solvent, mixing both of barium carbonate and scandium oxide having a layered crystalline structure into the solution to provide an suspension, pulverizing solid components of the suspension for the adjustment of particle size, and depositing the suspension on a surface of the base metal to form the electron emissive layer.

Abstract: This invention relates to an oxide-coated cathode for CRT and a manufacturing method thereof, where Scandium (Sc) or Scandium Oxide (Sc.sub.2 O.sub.3) is vaporized and ionized into a gas state under the oxygen existing environment, and is accelerated onto the surface of a base of Ni containing small amounts of a reducing element such as Mg or Si to form an implantation layer in a certain depth within the base, thereby enhancing the electron emissive characteristics and lengthening the longevity of the cathode.

Abstract: A metal layer of not more than 2.0 .mu.m thick is formed on a base, containing nickel as the main ingredient and a reducing agent such as silicon and magnesium, by depositing tungsten by an electron beam under heating in a vacuum. The base is heat treated in a hydrogen atmosphere at 800.degree. to 1,100.degree. C. An emissive material layer, containing an alkali earth metal oxide and 0.01 to 25 wt % of a rare earth metal oxide, the alkali earth metal oxide containing at least barium oxide, is formed on the metal layer. Thus, life characteristics of the cathode, especially during the operation at a high current density such as not less than 2A/cm.sub.2, are greatly enhanced.

Abstract: A high temperature low density operating element includes a porous high temperature operating element film formed into a predetermined configuration and disposed on one surface of an insulating member with good heat conductivity, a resistive film with a high melting point and good heat conductivity having a higher density than the high temperature operating element film, formed into a predetermined configuration on a second surface of the insulating member with good heat conductivity, a lead wire connected to the resistive film, an insulating protective film disposed on the insulating member covering the resistive film.

Abstract: A RF electron gun, such as for use in a linear electron accelerator, having a cathode activating device which, in one embodiment, includes means for altering the phase of the accelerating electric field to accelerate emitted electrons in the reverse direction to cause them to strike the cathode, thereby activating the cathode. In another embodiment, laser light is directed onto the cathode for activation thereof and, in a further embodiment, the electric field is positioned and directed at the cathode to cause the activation thereof.

Abstract: A field emission cathode device is disclosed herein and includes an array of electron emitting cathode tips supported by a base electrode or electrodes, a gate electrode spaced from and associated with each tip, and dielectric material located between each gate electrode and the base electrode of its associated cathode tip for insulating the two from one another. The device also includes means for establishing an electric field between the gate electrodes and tips sufficient to cause the tips to emit current. In addition, each electron emitting cathode tip is coated with an electrically conductive material that reduces its electron work function. At the same time, the dielectric material which insulates the base electrodes and gate electrodes from one another is maintained sufficiently free of the electron work function reducing material so as not to result in any appreciable current leakage between the base and gate electrodes. The specific method of coating the cathode tips is also disclosed herein.

Abstract: The emission properties of oxide cathodes, in which yttrium oxide, scandium oxide or a rare earth oxide is added to the electron-emissive material, are improved by using fine-grained yttrium, scandium or rare earth oxide.

Abstract: An electrode for discharge light source which is suitable for discharge display on account of its high reliability and outstanding discharge characteristics attributable to the metal conductor which is formed 1-5 .mu.m thick in the discharge container and also to the film of the material for secondary emission which is formed on the metal conductor from a compound composed of LaB.sub.6 and Ba in an amount of 0.01-20 mol % of LaB.sub.6 or a compound composed of LaB.sub.6, Ba in an amount of 0.01-20 mol % of LaB.sub.6, and Ca in an amount of 0.01-5 mol % of Ba, and is 0.5-2 .mu.m thick so that it is free of pin-holes.

Abstract: A cathode for an electron gun and its manufacturing method are disclosed. The cathode comprises thermoelectron emission substance layer composed of triple composite oxide of alkaline earth metal formed by thermally decomposing triple carbonate of alkaline earth metal such as barium, strontium and calcium, containing a fourth substance. The fourth substance consists of scandium nitrate or indium nitrate so that the fourth substance can be uniformly dispersed into the thermoelectron emission substance layer, and thus the thermoelectron emission characteristics and durability of the cathode can be remarkably enhanced.

Abstract: An electron-emitting device is provided which includes a laminate having an insulating layer held between a pair of electrodes opposing each other, wherein an electron-emitting region insulated from the electrodes is formed at a side end surface of the insulating layer formed at the part at which the electrodes oppose each other, and electrons are emitted from the electron-emitting region by applying a voltage between the electrodes. A method for preparing the electron-emitting device is also provided.

Abstract: The lifetime of oxide cathodes comprising, for example BaO and SrO as an emissive material, is improved by adding hafnium oxide or zirconium oxide.

Abstract: A solid-state electron beam generator has a hetero bipolar structure comprising an emitter region having a first band gap, a base region having a second band gap narrower than the first band gap, and a collector region having an electron-emitting surface. Electrons are injected from the emitter region into the base region while a backward bias voltage being applied between the base region and the collector region. In consequence, electrons are emitted from the electron-emitting surface of the collector region. The emitter region is constituted by an N-type Al.sub.x Ga.sub.1-x) As layer (0<x.ltoreq.1) having the first band gap and formed on an n-type or n.sup.+ -type GaAs substrate or a semi-insulating GaAs substrate, the base region is constituted by a P-type Al.sub.z Ga.sub.(1-z) As layer (0.ltoreq.z<x) having the second band gap, and the collector region is constituted by an n-type Al.sub.t Ga.sub.(1-t) As layer (0.ltoreq.t.ltoreq.1) formed on the n-type or n.sup.

Abstract: Cathode for an electric discharge tube having a short warm-up time and a long lifetime. The cathode comprises a metal (particularly nickel) support base coated with a layer of potentially electron-emissive material, which support base has a thickness ranging between 20 and 150 .mu.m, and metal crystallites having a size which does not permit of any further crystallite growth or recrystallization. Preferably, the crystallites of the support base have a size which corresponds to the thickness of the support base.

Abstract: This cathode has a body made of a material that does not emit electrons, having a substantially smooth non-emissive face and elements made of an emissive material each having an emissive face, spaced out from one another and fixed to the body, for example in hollows with their emissive surface in relief by a determined value with respect to said non-emissive face, so that a protection electrode can be placed between the projecting parts of these elements.

Abstract: A direct heating cathode includes an emitter for emitting electrons and a generally W shaped heater connected at opposite ends to terminals having a flat portion on which the emitter is mounted, bent portions at opposite sides of the flat portion, and an upwardly projected shoulder portion in the vicinity of each of the ends of the heater. Each of the bent portions of the heater includes two oppositely directed bends between the flat portion and the proximate heater end. The cathode structure elevates the temperature of the cathode at the position of the emitter, reducing power consumption and improving start-up speed, operational stability, and life expectancy.

Abstract: In order to bring a high power vacuum tube to full power in a few seconds, it is necessary to heat the cathode quickly to 1100.degree. C. In large tubes, prior art structures cannot be simply enlarged. A novel cathode structure in which the heater element is anisotropic pyrolytic graphite coated with anisotropic pyrolytic boron nitride for insulation and then sintered to the cathode avoids these problems.

Abstract: By providing at least the top layer of the matrix of a scandate cathode with an alloy or compound which exhibits scandium segregation, a satisfactory recovery for cathodes with a high emission can be achieved after ion bombardment.

Abstract: A directly heated cylindrical lanthanum boride cathode assembly is disclosed which minimizes generation of magnetic fields which would interfere with electron emission from the cathode. The cathode assembly comprises a lanthanum boride cylinder in electrical contact at one end with a central support shaft which functions as one electrode to carry current to the lanthanum boride cylinder and in electrical contact, at its opposite end with a second electrode which is coaxially position around the central support shaft so that magnetic fields generated by heater current flowing in one direction through the central support shaft are cancelled by an opposite magnetic field generated by current flowing through the lanthanum boride cylinder and the coaxial electrode in a direction opposite to the current flow in the central shaft.

Abstract: A cathode for an electron tube comprises a base (1) including nickel as a major element and including at least silicon as a reducing element, and it further comprises an electron-emissive layer (5) coated on the base, including not only alkaline earth metal oxide (8) containing at least barium but also scandium oxide. The scandium oxide (4) is in the form of dodecahedral or prismatic polyhedral crystals and dispersed in the electron-emissive layer in the range from 0.1 to 20 wt. %.

Abstract: A laser-triggered vacuum switch has a material such as a alkali metal halide on the cathode electrode for thermally activated field emission of electrons and ions upon interaction with a laser beam, the material being in contact with the cathode with a surface facing the discharge gap. The material is preferably a mixture of KCl and Ti powders. The laser may either shine directly on the material, preferably through a hole in the anode, or be directed to the material over a fiber optic cable.

Abstract: The present invention discloses an enhanced secondary electron emitter cathode suitable for use in a typical crossed-field amplifiers. The emitter surfaces of the cathode are formed into protuberances or knurls. The cathode's secondary emission characteristics are enhanced by providing protuberances with more surface area for electrons to bombard and for electrons to be emitted from. The protuberances increase the variety of angles of incidence of bombarding electrons thereby increasing the probability that bombarded electrons can escape the cathode's surfaces.

Abstract: A novel technique for mounting a disc of lanthanum hexaboride electron emission material within a hot cathode assembly of an electron gun is described. The disc is partly received in a recess of a graphite mounting member and the combined disc and mounting member are pushed to the end of a 50/50 molybdenum rhenium tube which has a rolled over lip which engages the disc. Indentations are formed in the tube and these extend into the mounting member to secure the mounting member to the tube. All contacting surfaces between the disc and mounting member and between the disc and lip are previously coated with colloidal graphite to improve electrical and thermal conductivity. Prior to securing the disc and mounting member to the tube the tube is secured to an alumina support ring by cutting and forming retaining lips from the tube and by flaring an end of the tube.

Abstract: According to the present invention, an impregnated cathode is provided wherein an alloy layer of iridium and tungsten is formed on a surface of a porous pellet impregnated with an oxide of an alkali earth metal, wherein a crystal structure of the alloy has an .epsilon.II phase comprising an hcp structure whose lattice constants a and c satisfy 2.76.ltoreq.a.ltoreq.2.78 and 4.44.ltoreq.c.ltoreq.4.46, respectively. The impregnated cathode of the present invention maintains stable electron emission characteristics from an early stage of operation.

Abstract: Beam generating system for electron beam measuring instruments. In prior art beam generators, the life expectancy of directly heated boride cathodes is limited by their thermally disadvantageous mount. The present invention provides a cathode not clamped at the lower end of the crystal shank as was previously standard, but clamped immediately below the cathode tip. The inventive mount of the boride cathode results in the crystal being only insignificantly hotter in the region of the clamping plane than at the electron-emitting tip.

Abstract: An oxide-coated cathode for an electron tube comprises a layer (2) of an electron-emissive substance. This layer (2) contains: an alkaline earth metal oxide as a principal component containing at least Ba; an oxide of Sc; and at least one heat-resisting oxide selected from the group consisting of oxides of Al, Si, Ta, V, Cr, Fe, Zr, Nb, Hf, Ta, Mo and W.

Abstract: A high emissivity cold cathode has alternating cylindrical tube layers, deposited by vapor deposition, of a refractory metal such as niobium and a refractory insulating material such as alumina. The metal layers have a thickness of less than or about 1,000 angstroms such that the electric field strength at the exposed end is sufficient, in combination with a low work function metal to emit electrons when a voltage of about 2,000 volts is applied.

Abstract: A long life cathode for laser generators consisting of a monolithic body of an agglomeration of oxidized metallic particles of beryllium or aluminum.

Abstract: An oxide cathode comprising a base 1 which consists substantially of titanium and a heater element 5 coated with aluminium oxide 6 to heat the base 1, which bears a porous alkaline earth metal oxide emissive layer 4. When the surface of the titanium base 1 which is opposed to the heater element 5 bears a metal layer 7 consisting at least of one of the metals Pt, Mo, Ta and W, a solution is obtained to the problem occurring in titanium cathodes in that titanium in contact with aluminium oxide is not chemically stable. The metal layer preferably consisits of pure tungsten and is formed by chemical vapour desposition (CVD). The metal layer is preferably from 1 to 10 .mu.m thick.

Abstract: In a vacuum electron tube, a novel oxide cathode comprising a metal substrate, means for heating said substrate to its operating temperature, and a layer of alkaline-earth-metal oxide on the substrate. The substrate is essentially free from silicon and contains operative concentrations greater than 1.0 weight % of chromium metal for progressively migrating into the oxide layer and reducing the oxide to yield alkaline-earth-metal.

Abstract: A hot cathode in a wire form is useful in a vacuum tube, a CRT or a fluorescent display tube is disclosed. The cathode is composed of a heat-resistant metal in a wire form that holds on it an electron-emitting metal material that is made of 0.2-20 wt % of a rear earth metal oxide in admixture with an alkaline earth metal oxide the balance of which contains at least barium oxide. The reduction of oxide barium to barium as a result of reaction with the cathode wire is so much retarded that an increased emission current will be produced from the cathode not only in its initial operation but also through out its operation.

Abstract: A tungsten-iridium billet is impregnated with a chemical mixture of barium xide, strontium oxide, and aluminum oxide, the impregnated billet heated, and the surface of the impregnated billet desired for emission exposed to an overcoating of rhodium.

Abstract: A cathode structure comprises a substrate including a porous sinter of a metal having a high melting point, which is impregnated with electron emitting material, a metal cup for receiving the substrate, a layer of solder disposed between the substrate and the metal cup, a covering layer disposed between the substrate and the solder layer and made of a metal having a melting point higher than that of the solder, a metal sleeve for supporting the metal cup, and a heater.

Abstract: A surface for electrical discharge for incorporation in a gas discharge chamber and designed to produce a uniform distribution of the field strength factor, and an increase in the photon and/or the electron density. This is achieved by employing a microstructure combining at least two materials of different physical properties and having a geometry which increases electron emission.

Abstract: An electroluminescent device is disclosed comprised of, in sequence, an anode, an organic hole transporting zone, an organic electron transporting zone, and a cathode. The cathode is comprised of a layer of a plurality of metals other than alkali metals, at least one of said metals having a work function of less than 4 eV.

Abstract: Electrodes for lamps comprising elongated structures comprised of layers containing varying amounts of metal and refractory oxide. In a preferred embodiment the electrode has a first end comprising 9.6 volume percent tungsten or molybdenum and the remainder alumina. The second end comprises substantially 100% tungsten. The intermediate body contains layers of, e.g., 12, 20, 35, 50 and 75% tungsten.

Abstract: An electron beam apparatus comprising a semiconductor electron emitter whose emissive surface dimensions are determined by dimensions of a p-n junction provided in the semiconductor element. By optimizing the dimensions of the emissive surface in relation to the electron-optical properties of the apparatus, an emitter is realized which combines optimum beam formation or imaging with a sufficiently large beam current and a high beam current density as required by the apparatus.

Abstract: A cathode for an electron tube in accordance with the present invention comprises: a base containing not only nickel as a major element but also a reducing agent; a layer of an electron-emissive substance which is applied to the base and contains not only an alkaline earth metal oxide as a principal component but also a scandium oxide; and a heater for heating the layer.

Abstract: An impregnated cathode comprising a cathode obtained by impregnating pore portions of a refractory porous substrate with an electron emissive material containing Ba and formed thereon a plurality of thin films made of a high melting metal and Sc, or a high melting metal and a Sc oxide, or a high melting metal, Sc and a Sc oxide, or a high melting metal and a compound of Sc, W and O, said thin films having the same composition but different densities can maintain good emission characteristics even after the sealing off step of tube production because the thin films formed on the cathode surface are oxidation-resistant.

Abstract: A cathode is formed such that a blackening of the inside wall of the discharge tube due to evaporated material does not occur and good heat transmission occurs. A base member (5) is provided to which a green sintered member (7) is pressed on said base member under high pressure and is then sintered which reduces its size. Soldering or welding is thus accordingly avoided. The volume of the sintered member (7) is significantly smaller than the volume of the base member (5).

Abstract: Improved anchoring of heating elements of a resistance heater to thermally stressed single crystals is achieved by embedding the individual heating element in a recess in the single crystal and permanently joining this to the heating element by a porous sintered composition. The sintered composition is formed by the heat treatment of a suspension that in addition to other components, contains material with the same chemical composition in powdered form as that of the single crystal.

Abstract: A method of treating a tungsten cathode that is comprised of coating the surface of the tungsten cathode with a triple carbonate suspension. The coated tungsten cathode is placed in a heated oxidizing environment (e.g., air, oxygen, or carbon dioxide) and heated for a sufficient amount of time in order to form a diffuse coating of triple carbonates and tungsten oxide. Thereafter, the triple carbonates are reduced to their respective oxides by passing heater current through the tungsten cathode. When used in conjunction with the manufacture of a fluorescent lamp, the formation of this diffuse coating of carbonates enhances the chances of forming barium tungstate during the cathode activation process. As a result, the life of the fluorescent lamp is increased and the amount of phosphor darkening is reduced.

Abstract: An impregnated cathode which has a portion where no electron emissive material is present on the surface layer of the cathode base body that is to be welded, in order that the cathode base body impregnated with the electron emissive material, a cup and a cathode sleeve can be firmly welded together. The cathode base body which has no electron emissive material on the surface layer is obtained by washing the cathode base body in a solvent which is capable of dissolving the electron emissive material. Using this cathode base body, the impregnated cathode is fabricated.

Abstract: A four-piece, easily manufactured dispenser cathode capable of current densities up to and exceeding 10 Amperes per square centimeter is particularly adapted for CRT applications because of its surprisingly low cost. A refractory material reservoir contains a pellet of tungsten and barium calcium aluminate and is sealed by a pellet of porous tungsten or tungsten mixture. The reservoir/pellet assembly is contained in a support cylinder to which the porous tungsten pellet may be welded. The inventive process includes the steps to prepare the pellets and assemble the four elements of the cathode.

Abstract: An extremely long-life, highly reproducible cathode is produced by preparing a porous sintered metal matrix, impregnating the matrix with a reagent containing a transition metal to modify the surface structure of the matrix, and then impregnating the surface-modified metal matrix with a barium-containing reagent to produce a cathode structure in which barium atoms are held in a metal-metal interaction with the transition metals and the surface of the matrix. In a preferred embodiment, the transition metal oxide is TiO.sub.2. This produces a barium/transition metal oxide surface structure which permits cathode operating temperatures on the order of 650 degrees C. The barium is stable and is retained on the surface of the metal matrix, so further dispensing is not required.

Abstract: A contact for a semiconductor cathode is produced by thermally bonding leads consisting of one of the metals Ag, Au, Cu and one of the metals Ta, Ti, V. Such a contact does not exhibit degradation when the cathode, after mounting in a vacuum tube, is heated several times to approximately 850.degree. C. for cleaning purposes.

Abstract: By providing an intrinsic semiconductor region in a reverse biased junction cathode between an n-type surface region and a p-type zone, a maximum field is present over the intrinsic region in the operating condition. The efficiency of the cathode is increased because avalanche multiplication can now occur over a greater distance, while in addition electrons to be emitted at a sufficient energy are generated by means of tunneling.

Abstract: This invention is a cathode of an indirect heated type having improved electron emission characteristics.A cathode for an electron tube in accordance with the present invention comprises: a base containing Ni as a major element; and a layer of an electron-emissive substance formed on the base, this layer comprising not only alkaline earth metal oxide as a principal component containing at least Ba, but also rare earth metal oxide of 0.1 to 20 wt. % or rare earth metal of 0.05 to 15 wt. %.

Abstract: A large area directly heated lanthanum hexaboride (LaB.sub.6) cathode system (10) is disclosed. The system comprises a LaB.sub.6 cathode element (11) generally circular in shape about a central axis. The cathode element (11) has a head (21) with an upper substantially planar emission surface (23), and a lower downwardly and an intermediate body portion (26) which diminishes in cross-section from the head (21) towards the base (22) of the cathode element (11). A central rod (14) is connected to the base (22) of the cathode element (11) and extends along the central axis. Plural upstanding spring fingers (37) are urged against an outer peripheral contact surface (24) of the head end (21) to provide a mechanical and electrical connection to the cathode element (11).