59results about "Thermionic cathode manufacture" patented technology

The invention provides heat pump comprising a chamber for accommodating electrically charged or chargeable particles, having a thermal conductive wall, and an electrically insulating sink wall. A resistive layer made of electrical resistive material, is positioned outside the chamber with one of its faces proximal to the sink wall. The chargeable particles hit the internal surface of the sink wall, and the thermal conductive wall is in thermal communication with the particles. Thermal fluctuations of the charged particle in the chamber induce variable electric field on the resistive layer, which is harvested into electric current.

The application discloses a CT cathode tube cathode surface coating and a preparation method thereof. The coating is prepared by improving a magnetron sputtering process, using iridium (Ir) and osmium (Os) as metal targets, and depositing a metal coating with a thickness of 10-20 microns on a molybdenum base. The prepared metal coating has a bonding force to the base which can exceed 100 N, and the coating is dense and has good uniformity, and can be used as a cathode for exciting electrons on the surface of a cathode tube in a CT X-ray tube.

The present invention is titled Methods and Systems for an X-ray Tube with Texture. The present invention provides various methods and systems for a cathode cup having surface texturing that aids in adhering an emitter deposition film. In one embodiment, a method may include chemically and / or mechanically texturing a surface of the cathode cup to form a plurality of features, each feature having a depth above a threshold, the surface of the cathode cup facing an emitter coupled to the cathode cup.

The present application relates to a kind of hafnium foil for electric vacuum device and its preparation method, belong to microwave vacuum electron technology and refractory metal powder metallurgy field.The hafnium foil main content (hafnium+zirconium) ≥99.9wt%, thickness 0.01mm~0.15mm, size tolerance ≤±5 μm, tensile strength ≥450MPa, elongation after breaking ≥15%, main texture is <10‑10> / / RD.Preparation method includes: iodization purification, electron beam melting obtains high-purity hafnium ingot, is obtained foil material blank by hot forging breakdown, cross hot rolling, cross cold rolling, finally by vacuum stress relief annealing, cutting inspection and is prepared hafnium foil.The hafnium foil of the present application is high in purity, high in dimensional accuracy, strong and tough, isotropic degree is good, can be used for grid traveling wave tube spherical structure grid and other electric vacuum devices.

This invention provides an X-ray tube filament winding mold and a filament manufacturing method. The winding mold includes a first main mold, a second main mold, and a clamping plate. Both the first and second main molds are cylindrical. The front end of the first main mold and the rear end of the second main mold each have two positioning holes. Angular grooves are formed on both sides of the first main mold, symmetrically opposite in direction, with pin holes at the rear of the grooves. Two positioning pins are provided in the two positioning holes at the front end of the first main mold. The front end of the first main mold and the rear end of the second main mold can be connected by the positioning pins. The first and second main molds are fixed together by the clamping plate. Using the filament winding mold, a coil-shaped X-ray tube filament, distinct from a long, spiral filament, can be regularly wound. The filament winding mold has a simple structure, low manufacturing cost, is easy to use, has a high reusability rate, long lifespan, and wide applicability. The wound filament has a small and regular emission surface, resulting in a relatively concentrated spatial distribution of emitted electrons, making it easy to focus and improving the spatial resolution of image reconstruction.

The invention discloses a hot cathode for a vacuum device and a preparation method and application of the hot cathode. The structure of the hot cathode comprises a cathode substrate and an emission active material combined on the cathode substrate; wherein the cathode substrate is of a porous structure, and the cathode substrate is made of a mixture of chromic oxide and tungsten; and the emission active material is scandium-containing barium aluminate. According to the scheme, the problem that the requirement of a current high-power vacuum electronic device for a low-working-temperature and high-emission-current-density electron source cannot be met is well solved.

The current stability of a field emission electron source and a Schottky electron source where a {100} plane of a hexaboride single crystal is used as an electron emission surface is improved. The electron source includes a tip of a hexaboride single crystal with a <100> axis, in which a top facet of a {100} plane that is surrounded by side facets including at least four {n11} planes and at least four {n10} planes where n represents an integer of 1, 2, or 3 is formed at a front end of the tip of the hexaboride single crystal, and a total area of the side facets of the {n11} planes is more than a total area of the side facets of the {n10} planes.

A cathode heater assembly for use in a vacuum electronic device comprises a refractive cup having a bottom portion and side walls forming a container: a cathode secured in the container of the refractive cup; and a heater wire coupled to the refractive cup. The cathode heater assembly may be manufactured by providing a refractive cup having a bottom portion and side walls forming a container; inserting a cathode pellet in the container of the refractive cup; impregnating the cathode pellet with electron emissive materials while the cathode pellet is in the container of the refractive cup; and attaching a heater wire to the refractive cup.

The invention provides a composite film M-type hot cathode and a preparation method thereof. The composite film layer M-type hot cathode comprises a barium tungsten cathode substrate, a Re3W alloy phase barrier layer and a noble metal surface layer, and the Re3W alloy phase barrier layer is formed between the barium-tungsten cathode substrate and the noble metal surface layer. The composite film layer M-type thermionic cathode can effectively prevent alloying between the tungsten substrate and the precious metal film layer, so that the emission capability of the cathode is improved, and the service life of the cathode is prolonged.

An electron source according to the present disclosure includes a columnar portion made of a first material having an electron emission characteristic; and a tubular portion that is disposed to surround the columnar portion and made of a second material having a higher work function than the first material, wherein a hole that extends in a direction from one end face toward the other end face and has a substantially circular cross-sectional shape is formed in the tubular portion, and the columnar portion has a substantially triangular or substantially quadrangular cross-sectional shape and is fixed to the tubular portion in an abutting engagement with an inner surface of the hole.

The present application relates to an electron gun, which has a cathode having an electron emission surface, a planar shape of which is circular, and which emits electrons, a heater which warms the cathode, and an anode which applies a positive potential to the cathode and extracts the electrons in a certain direction. The cathode has a through-hole along a central axis of the cathode in a central portion thereof, and at least one of an opening edge portion of the through-hole on the electron emission surface side and an inner surface of the through-hole has a non-emission layer, or the opening edge portion of the through-hole on the electron emission surface side is a chamfered C face or a chamfered R face.

The invention provides a scandate active material with high Sc2O3 content and application thereof in an impregnated diffusion cathode, and belongs to the technical field of manufacturing of thermal diffusion cathodes for vacuum electronic devices, and the scandate active material is obtained by mixing BaCO3, CaCO3, Al2O3 and Sc2O3 according to a molar ratio of 12: 2: 3: 1, grinding, pressing into a sheet, heating to 1100-1150 DEG C in air, sintering for 24-48 hours, cooling and grinding. By optimizing the proportion of the components, the scandate active substance with the Sc2O3 mole percentage exceeding 5.5% is obtained, and the scandate active substance does not contain an ineffective active substance BaAl2O4, so that the emission performance of the impregnated diffusion cathode is improved; the composite material is applied to an impregnated diffusion cathode, and cathode surface modification treatment is carried out in combination with a surface etching technology, so that pore blockage caused by mechanical polishing or processing is effectively eliminated, and synchronous improvement of cathode emission current density and working stability is realized.

A method for manufacturing an electron source according to the present disclosure includes steps of: (A) preparing a first member provided with a columnar portion made of a first material having an electron emission characteristic, (B) preparing a second member which has a higher work function and a lower strength than the first material, and in which a hole is formed extending in a direction from one end surface toward the other end surface, and (C) pushing the columnar portion into the hole in the second member, wherein the first member has a cross-sectional shape that is dissimilar to the cross-sectional shape of the hole; and in the step (C), by pressing the columnar portion into the hole, a portion of a side surface of the columnar portion scrapes the inner surface of the hole and bites into the second member, thereby fixing the columnar portion to the second member.

The application provides a cathode heater subassembly for a traveling wave tube and a preparation method, and belongs to the technical field of electric vacuum devices. The cathode heater subassembly comprises a cathode cake, a solid spherical cathode used as an electron source of the traveling wave tube to emit electrons; a heater, a composite structure composed of a boron nitride insulating layer, a graphite electrode layer and a boron nitride covering layer, the graphite electrode layer is located between the boron nitride insulating layer and the boron nitride covering layer, the graphite electrode layer is a single helix structure, the boron nitride insulating layer is brazed to the bottom of the cathode cake, and the heater is used for heating the cathode cake; a heater lead, comprising a first heater lead and a second heater lead, the first heater lead is brazed to a first end of the single helix structure of the graphite electrode layer through the boron nitride covering layer, the second heater lead is brazed to a second end of the single helix structure of the graphite electrode layer through the boron nitride covering layer, the first end is a position away from the center of the single helix structure of the graphite electrode layer, and the second end is a position close to the center of the single helix structure of the graphite electrode layer.

The present application relates to a cathode and a manufacturing method thereof. The method includes: mixing and reacting cations containing a cathode element with a precipitant in a solution to obtain a gelatinous precipitate; and coating the gelatinous precipitate on a surface of a cathode substrate, which is configured for forming the cathode.

The invention provides an active substance for a dipping diffusion cathode, the dipping diffusion cathode and a preparation method of the dipping diffusion cathode, and relates to the technical field of dipping diffusion cathode active materials and vacuum electronic device manufacturing. The preparation method of the active substance for dipping the diffusion cathode comprises the following steps: preparing an aqueous solution by taking at least one of water-soluble acetate, nitrate, gluconate, formate and lactate of barium, calcium, aluminum and cerium elements in a molar ratio of (25-40): (2-20): (10-25): (5-20) as a raw material; drying the aqueous solution to obtain a precursor powder material; placing the precursor powder in a protective atmosphere, and heating for 1-4 hours in an environment of 800-1000 DEG C; the invention further provides the active material for the impregnated diffusion cathode, the impregnated diffusion cathode and a preparation method of the impregnated diffusion cathode.

The application discloses a kind of solder, solder slurry, magnetron cathode assembly and preparation method thereof, it is related to magnetron cathode assembly field.Therein, solder is obtained by 15-40wt% tungsten, 30-60wt% molybdenum and 15-40wt% nickel mixed ball milling.Solder slurry includes organic carrier, solvent and solder, organic carrier is 5-15% of the weight of the solder, solvent is 5-20% of the weight of the solder.Lamp filament and molybdenum end cap in magnetron cathode assembly are brazed using the above-mentioned solder, specific operation method is that solder slurry is coated on molybdenum end cap, sintering forms solder layer, then again heating melts solder layer to weld and fix lamp filament and molybdenum end cap.The solder in the present application has the advantages of low cost, low brazing temperature and wide range, low vapor pressure, can improve the welding effect of lamp filament and molybdenum end cap while reducing the bubbling probability of molybdenum end cap, so as to improve the qualified rate of finished product of magnetron cathode assembly.

To provide an electron source which can have sufficient electron emission characteristics even after a certain time elapses from start of emission of electrons, and to provide a manufacturing method of the electron source.SOLUTION: An electron source 100 includes: an electron emission member 10 containing iridium and lanthanoid; a conductive support member 20 which supports the electron emission member 10; and a conductive member 30 disposed between the electron emission member 10 and the support member 20 and in contact with both. In a manufacturing method of the electron source 100, the electron emission member 10 and the support member 20 are joined through the conductive member 30.SELECTED DRAWING: Figure 2

To provide an indirect heated cathode capable of shortening the time up to a start of radiation of thermoelectrons, and a method of manufacturing the indirect heated cathode in which a heat absorption layer which has a uniform thickness can be easily manufactured.SOLUTION: An indirect heated cathode 10 comprises a cathode sleeve 1, a heater 2 arranged at a hollow part of the cathode sleeve 1, a black heat absorption layer 4 covering a hollow part inner surface of the cathode sleeve 1, and a cathode base body 3 carrying an electron emission substance arranged at the cathode sleeve 1. The black heat absorption layer 4 consists of a particulate substance including tungsten and aluminum oxide. The black heat absorption layer 4 is formed by arranging rod-like alumina ceramics, and a first tungsten heater and a second tungsten heater in the hollow part of the cathode sleeve 1 and heating it in a vacuum atmosphere.SELECTED DRAWING: Figure 1

This invention discloses an oxide cathode and its sintering apparatus. The oxide cathode includes a cathode cylinder and a porous sponge layer. The cathode cylinder has two annular stepped surfaces, which are spaced apart from each other along the axial direction of the cathode cylinder. The cathode cylinder also has a sintering region located between the two stepped surfaces. The sponge layer is disposed within the sintering region, with its two ends respectively attached to the two stepped surfaces. Simultaneously, the sponge layer does not protrude from the stepped surfaces radially within the cathode cylinder. This invention can effectively suppress the axial scattering of electrons from the non-emission region of the oxide cathode, reduce interference with high-frequency fields, reduce the bombardment of the magnetron anode end cap by scattered electrons from the non-emission region, effectively solve the oxidation problem of the anode end cap during magnetron use, and improve the overall performance of the magnetron.

A monolithic graphite heater for heating a thermionic electron cathode includes first and second electrically conductive arms, each one of the first and second electrically conductive arms having an electrode mount at a proximal end, a thermal apex at a distal end, and a transitional region between the electrode mount and the thermal apex; a cathode mount electrically and mechanically coupling each thermal apex to form a maximum Joule-heating region at or adjacent the cathode mount and decreasing Joule heating along each transitional region; and a press-fit aperture formed in the cathode mount, the press-fit aperture sized to receive at least a portion of the thermionic electron cathode for facilitating thermionic emission produced therefrom in response to operative heat power generation provided by the maximum Joule-heating region.

To provide an emitter which can effectively suppress generation of excess electrons and can improve structural stability, while suppressing variation in electron emission characteristics.SOLUTION: An emitter comprises: an electron source 2; and a heater 3 for heating the electron source 2. The electron source 2 has: an electron emission member 10 which is made of a first material; and a surrounding member 20 which is made of a second material having a work function greater than that of the first material. The electron emission member 10 has: a first portion 11; and a second portion 12 which is made integral with the first portion 11. The surrounding member 20 is fixed to the electron emission member 10, and it surrounds the first portion 11 when viewed from a direction A. The minimum thickness of the surrounding member 20 is 20 μm or more. The heater 3 is in contact with the second portion 12.SELECTED DRAWING: Figure 2

The invention relates to a hafnium foil for an electric vacuum device and a preparation method of the hafnium foil, and belongs to the field of microwave vacuum electronic technology and refractory metal powder metallurgy. The main content (hafnium + zirconium) of the hafnium foil is greater than or equal to 99.9 wt%, the thickness is 0.01-0.15 mm, the dimensional tolerance is less than or equal to + / -5 microns, the tensile strength is greater than or equal to 450 MPa, the percentage elongation after fracture is greater than or equal to 15%, and the main texture is lt; 10 <-10 > gt; / / RD. The preparation method comprises the following steps: performing iodination purification and electron beam melting to obtain a high-purity hafnium ingot, performing hot forging cogging, cross hot rolling and cross cold rolling to obtain a foil blank, and finally performing vacuum stress relief annealing and cutting inspection to obtain the hafnium foil. The hafnium foil disclosed by the invention is high in purity, high in dimensional precision, matched in strength and toughness and good in isotropy, and can be used for electric vacuum devices such as a grid-control traveling wave tube spherical structure grid mesh and the like.

To provide a novel low-work function material which has low chemical reactivity to lanthanoid-based boride known as a low-work function material, especially, a low-work function material which can have its surface purified at a lower heating temperature than before after being exposed to atmospheric gas.SOLUTION: The present invention relates to a laminate which has its surface coated with a thin film and includes a lanthanoid-based boride film formed on a substrate, the thin film being a hexagonal boron nitride thin film of a monoatomic layer.SELECTED DRAWING: None

The present invention discloses a cathode heater assembly for a high-power pulse magnetron, a preparation method, and applications. The assembly comprises a tungsten wire wound into a desired shape, followed by a primary high-temperature shaping step, an insulating layer coating, and a secondary high-temperature sintering step to produce the desired heater. A cathode blank with a tantalum sponge is prepared; a cathode preform with a tantalum sponge is coated with a composite rare earth oxide suspension and sintered in a high-temperature vacuum furnace to produce the desired cathode. The cathode and heater are assembled, and the space between the cathode and heater is filled with a thermally conductive and electrically conductive material before being sintered in a vacuum furnace to produce the cathode heater assembly. The cathode heater assembly of the present invention exhibits high thermal emission and secondary electron emission, and good resistance to electron and ion bombardment, thereby extending its service life while adapting to the operating environment of a high-power pulse magnetron. The assembly also features low cathode heating power, high thermal emission current density, and rapid startup.

The cathode member for electron beam generation of the present disclosure includes: 95% by area or more of a single phase or two phases of a compound composed of iridium and cerium. A total content of one or more subcomponents of metallic iridium and an oxide of one or more elements of iridium and cerium is 5% by area or less of the cathode member.

The invention discloses a preparation method of an impregnated cathode and the impregnated cathode. The preparation method comprises the following steps: obtaining a heater assembly with a porous tungsten sponge body; reducing powder and an active substance are mixed according to the set mass ratio to form mixed powder, and the active substance can be reduced by the porous tungsten sponge body and the reducing powder respectively; inverting the heater assembly to enable the porous tungsten sponge body to be placed in the molybdenum boat, fixing the heater assembly, and adding a proper amount of mixed powder into the molybdenum boat to bury the porous tungsten sponge body; placing the molybdenum boat in which the heater assembly is placed in a hydrogen furnace, preserving heat for a set time according to a set temperature to melt the active substance, and impregnating the active substance and the reducing powder in holes of the porous tungsten sponge body to form an impregnated cathode; the heater assembly is taken out and the surface of the impregnated cathode is polished. According to the method, enough free barium can be generated at a relatively low temperature and transported to the emission surface, so that the production rate of the free barium is increased, the work function of the emission surface is reduced, and the emission capability is improved.

The invention provides an assembly tool and an assembly method for a hot cathode filament, the assembly tool comprises a half base and a welding pressing block tool which are symmetrically arranged left and right, the half base is provided with a filament groove and two pin limiting tables, the size of the filament groove is accurately matched with the diameter of the filament, and an annular step of a conductive pin is limited on the pin limiting tables; the welding pressing block tool comprises a first pressing block and a second pressing block, and the first pressing block is used for limiting the transverse position of the lamp filament; one end of an L-shaped convex block on the second pressing block presses the lamp filament in the lamp filament groove, and the other end of the L-shaped convex block reserves an enough space, so that the lamp filament can be welded conveniently; and the welding of the other welding end of the lamp filament is realized by exchanging the positions of the first pressing block and the second pressing block. According to the invention, the symmetrically arranged Haff bases effectively control the position and deformation of the lamp filament in the assembly process, the unique design of the welding pressing block tool limits the transverse and longitudinal movement of the lamp filament, the welding space is reserved, and the position accuracy and consistency of lamp filament assembly are remarkably improved.

The application belongs to the technical field of lamp tube activation, and particularly relates to a bidirectional electrode activation machine, which comprises a machine table. An upper feeding mechanism, a rotating disc conveying mechanism, a discharging mechanism, a turnover mechanism and a lower discharging mechanism are arranged on the machine table. The upper feeding mechanism is arranged on one side of the rotating disc conveying mechanism and is used for conveying lamp tubes to the rotating disc conveying mechanism. The turnover mechanism is arranged on one side of the rotating disc conveying mechanism and is used for overturning the lamp tubes on the rotating disc conveying mechanism. The discharging mechanism is arranged at the upper end of the rotating disc conveying mechanism, the rotating disc conveying mechanism is used for conveying the lamp tubes to the working end of the discharging mechanism, and then the discharging mechanism discharges and activates the lamp tubes. The lower discharging mechanism is arranged on one side of the rotating disc conveying mechanism, the rotating disc conveying mechanism sequentially passes through the upper feeding mechanism, the discharging mechanism, the turnover mechanism, the discharging mechanism again and the lower discharging mechanism, and the lower discharging mechanism is used for picking up the activated lamp tubes on the rotating disc conveying mechanism. The turnover mechanism can overturn the lamp tubes, thereby reducing the labor intensity of workers.