36results 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 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 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.

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 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 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.

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 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 present application relates to a layered cathode structure based on the alternative distribution of functional layers-buffer layers and its rapid trial method, belongs to the field of mechanical processing technology, and relates to a layered cathode structure comprising a functional structure surface layer and a matrix, wherein the functional structure surface layer is further composed of a plurality of sub-functional layers and buffer layers stacked and arranged alternately. In actual service, the functional layer made of thermo-chemical materials generates refractory oxide layer in situ to complete self-protection and emit electron support arc discharge; the buffer layer is made of nanocrystalline material with high plastic deformation ability, which can not only release the thermal stress of the functional layer by its own moderate deformation, but also accelerate the migration of the cathode spot to slow down the cathode burning loss when contacting the cathode arc. By utilizing the synergistic effect of the functional layer and the buffer layer, the cracking, splitting and coating peeling problems caused by plasma discharge rapid heating and rapid cooling in the application scenarios such as hole drilling by electric spark machining and arc welding of the layered cathode are solved, and the ablation uniformity is improved and the ablation rate is reduced.

A method for producing a sintered material, the sintered material being constituted by iridium and cerium, and the method including: a step of preparing a sintered body constituted by iridium and cerium; and a step of heating the sintered body at a temperature of 1400 to 1800°C for 0.5 hours or more in an atmosphere having an oxygen partial pressure of 10-1 Pa or less to obtain the sintered material. A sintered material constituted by iridium and cerium, having a work function of 3.8 eV or less.

The present invention provides a method for manufacturing an electron source having a structure in which a tip of an electron-emitting material is directly bonded to a tungsten filament. [Solution] A method for manufacturing an electron source includes the steps of sandwiching a workpiece, which is superimposed so that the tip of an electron-emitting material and the tungsten filament are in direct contact with each other, between a pair of welding electrodes, and welding the tip and the tungsten filament by applying a pressing force to the workpiece with the pair of welding electrodes while passing an electric current through the workpiece, and the thickness of the workpiece is in the range of 50 to 500 μm.

The present invention provides an aluminum carbide alloy filament and its manufacturing method, a heating device, and relates to the technical field of filament cathode materials. The aluminum carbide alloy filament includes a matrix (100) and a carbide layer (200) attached to the outer surface of the matrix (100). The carbide layer (200) has a grain width of 1.0 μm to 15.0 μm. The components of both the matrix (100) and the carbide layer (200) include tungsten, carbon, oxygen, and an M element, where the M element is one or a combination of elements selected from the group consisting of La, Y, Sc, Nd, Sm, Lu, Ce, Gd, Tb, Dy, Ho, Pr, Er, Tm, Yb, Eu, Hf, and Zr. The tungsten carbide alloy filament does not include thorium. This material improves the emission stability of tungsten alloy filaments and achieves the stable emission capability of conventional thorium-tungsten filaments without adding thorium, solving the problem of the relatively poor stable emission capability of existing thorium-free tungsten filaments and also eliminating the problem of radioactive contamination that occurs with conventional thorium-tungsten filaments.

The purpose of the present invention, relating to lanthanide boride, which is known as a low work function material, is to provide a novel low work function material with low chemical reactivity, in particular a low work function material of which the material surface, after being exposed to atmospheric gases, can be cleaned at a heating temperature lower than in the prior art. The present invention is a laminate containing a lanthanide boride film formed on a substrate, the surface of said film being covered by a thin film, wherein the thin film is a monatomic layer of a hexagonal boron nitride thin film.

The invention discloses a thermal deformation compensation method for a cathode filament of an X-ray tube, and relates to the technical field of X-ray tubes. According to the thermal deformation compensation method of the X-ray tube cathode filament, the X-ray tube cathode filament comprises a filament body and filament pins formed at the two ends of the filament body, and the ends, close to the filament body, of the filament pins form filament pin heads. One end, far away from the lamp filament main body, of each lamp filament pin forms a lamp filament pin tail part; the thermal deformation compensation method for the cathode filament of the X-ray tube comprises the following steps: S1, establishing an initial cold state simulation model of the cathode filament of the X-ray tube, and performing thermal deformation simulation analysis on the cathode filament of the X-ray tube; and S2, processing the cathode filament of the X-ray tube based on the result of the thermal deformation simulation analysis. According to the invention, dynamic reverse pre-compensation can be accurately carried out on the thermal state deformation of the filament, and the stability of the cathode filament in a geometric state in a working thermal state is improved.

The invention provides a cathode assembly, a preparation method thereof and an electric thruster. The cathode assembly comprises a metal part, a boride ceramic part and a composite layer, the metal part and the boride ceramic part are connected through the composite layer, the composite layer comprises a carbide ceramic transition layer and a brazing layer which are arranged in a stacked mode, and the carbide ceramic transition layer is arranged between the connecting face of the boride ceramic part and the brazing layer. The brazing layer is arranged between the carbide ceramic transition layer and the connecting face of the metal part. Therefore, the service life and the reliability of the cathode assembly can be improved.

The invention belongs to the technical field of electric light source materials and manufacturing, and discloses a thorium-free cathode for a short arc discharge lamp and a preparation method and application of the thorium-free cathode. The preparation method of the thorium-free cathode for the short-arc discharge lamp comprises the following steps: S1, mixing raw materials and carrying out drying treatment; s2, the dried mixed powder is subjected to reduction treatment in a reducing atmosphere, and tungsten alloy powder is obtained; s3, the tungsten alloy powder is subjected to compression molding, sintering and vertical sintering, and a cathode blank is obtained; s4, the cathode blank is forged, and a cathode base body is obtained; and S5, a groove with an inverted triangular cross section is machined in the middle section of the cathode base body in the direction of the center axis of the cathode base body, and the thorium-free cathode for the short arc discharge lamp is obtained. According to the preparation method of the thorium-free cathode for the short-arc discharge lamp, through collaborative optimization of a material system and structural design, comprehensive improvement of the electron emission performance, the thermal stability and the service life of the cathode is achieved.

The invention belongs to the technical field of electric light source manufacturing, and discloses a thorium-tungsten cathode for a short-arc discharge lamp and a preparation method and application of the thorium-tungsten cathode. The preparation method of the thorium-tungsten cathode for the short arc discharge lamp comprises the following steps: S1, coating the surface of a thorium-tungsten cathode substrate with a heat treatment solution to obtain the thorium-tungsten cathode comprising a carbon source coating; and S2, carrying out segmented heat treatment on the thorium-tungsten cathode comprising the carbon source coating, and cooling to obtain the thorium-tungsten cathode for the short arc discharge lamp. According to the preparation method of the thorium-tungsten cathode for the short-arc discharge lamp, through specific material and process design, the surface components and the structure of the thorium-tungsten cathode are synergistically optimized on the microscopic level, the emission capability, the thermal erosion resistance and the long-term structural stability of the thorium-tungsten cathode are enhanced, and the comprehensive improvement of the short-arc discharge light output performance is jointly realized.

The invention relates to the technical field of electronic optical equipment and micro-nano machining, and discloses a field emission electron source. The field emission electron source is mainly composed of a filament base, a binding post, a welding post, a welding groove, a tungsten sheet, an emission tungsten needle and the like. During welding, the tungsten sheet is in direct contact with the side wall of the welding groove, so that original point contact between the tungsten filament and the welding column is replaced by surface contact by contact between the tungsten sheet and the side wall of the welding groove, the welding area is increased, the conditions of pseudo soldering, unsoldering and the like are reduced, and the welding quality and reliability are greatly improved; and two or more tungsten sheet welding structures can disperse thermal stress generated in the heating process to a plurality of welding spots, deformation of a single welding spot due to stress concentration can be avoided, the position offset of the emission tungsten needle is prevented, and then the emission stability of the electron source can still be ensured in a long-term heating environment.

A method for producing a sintered material comprising iridium and cerium, the method comprising: a step for preparing a sintered body comprising iridium and cerium; and a step for obtaining a sintered material by heat-treating the sintered body for 0.5 hours or more at a temperature of 1400-1800 DEG C in an atmosphere having an oxygen partial pressure of 10-1 Pa or less. And a sintered material comprising iridium and cerium and having a work function of 3.8 eV or less.

The invention belongs to the field of microwave vacuum electronic technology and refractory metal powder metallurgy, and particularly relates to a tungsten-scandium mixed matrix for a high-power hot cathode and a preparation method and application of the tungsten-scandium mixed matrix. The porosity of through holes of the tungsten-scandium mixed matrix is 18-30%, the average aperture is 0.3-2.0 microns, the scandium oxide content is 1-10 wt%, the percentage of closed area is smaller than or equal to 1%, and the specific surface area of the tungsten-scandium mixed matrix is smaller than or equal to 1%. And the grain size of the scandium oxide in the mixed matrix is not more than 1 mu m after sintering. The preparation method comprises the steps of tungsten powder grading, grinding and coating, vacuum drying, reduction purification, sieving, blending, cold isostatic pressing forming, hydrogen pre-sintering, precision machining, hydrogen high-temperature sintering and the like. In addition, the tungsten-scandium mixed substrate prepared by the method can be applied to scenes such as high-power terahertz devices and the like, and can replace a conventional M-type impregnated barium-tungsten cathode.