138results about "Discharge tube solid thermionic cathodes" patented technology

The embodiment of the utility model provides a cathode assembly and an electron emission device. The cathode assembly comprises a cathode emitter, the first end of the cathode emitter is used for emitting electrons outwards, and the material of the cathode emitter at least comprises boride; the first heating part is used for irradiating the cathode emitter with laser so as to heat the cathode emitter; the second heating part is connected to the second end of the cathode emitter, and the second heating part heats the cathode emitter by generating joule heat; and the second heating component is used for heating the cathode emitter together with the first heating component after the first heating component heats the cathode emitter to a first temperature threshold value.

A filament assembly 10 for an x-ray tube 20 can include a planar filament 11 electrically-coupled between and substantially-encircled by a pair of collector plates C1 and C2. The pair of collector plates C1 and C2 can support the planar filament 11 so that it does not twist or warp and align the filament assembly 10 within a cathode cup 33. The pair of collector plates C1 and C2 can block electrons emitted from a back side of the filament. Without the collector plates C1 and C2, back side electrons can change direction by about 180°, hit the target, and distort a target electron spot. Each collector plate C1 or C2 can include holes H1 and H2. These holes H1 and H2 can aid in alignment of the collector plates C1 and C2 with electrodes 31 and electrode 32, can allow welding at a lower temperature, and can facilitate weld inspection.

The invention relates to a layered cathode structure based on functional layer-buffer layer alternate distribution and a rapid trial-manufacturing method thereof, and belongs to the technical field of machining, the layered cathode structure comprises a functional structure surface layer and a matrix, and the functional structure surface layer is further formed by stacking and alternately arranging a plurality of sub functional layers and buffer layers. In actual service, a refractory oxide layer is generated in situ on the basis of the functional layer made of the thermochemical material, self-protection is completed, and electrons are emitted to support arc discharge; and the buffer layer is made of a nanocrystalline material with high plastic deformation capacity, so that the thermal stress of the functional layer can be released through proper deformation of the buffer layer, and meanwhile, cathode spot migration can be accelerated when the buffer layer is in contact with a cathode arc so as to slow down cathode burning loss. Through the synergistic effect of the functional layer and the buffer layer, the problems of cracking, splitting and coating falling caused by plasma discharge shock heating and shock cooling of the layered cathode in application scenes such as electric spark machining hole making and electric arc welding are solved, meanwhile, the ablation uniformity is improved, and the ablation rate is reduced.

To provide an electron source that can improve the temperature stability of an electron emission part during heating, and an electron gun and an electronic device including the same.SOLUTION: An electron source includes an electron emission part containing an alloy of iridium and rare earth elements, a support part made of metal, and a joint part that joins the electron emission part and the support part. The joint part includes a coating layer containing iridium and metal in the support part.SELECTED DRAWING: Figure 1

The invention relates to an electron extraction method and system for a low-energy electron source. The method comprises the following steps: providing at least one cathode, at least one heating power supply and at least one control electrode; in a first time period, the heating power supply provides heating current for the cathode, so that the temperature of the cathode is increased to be higher than an electron emission threshold value, meanwhile, the potential difference between the control electrode and the cathode is controlled to be a suppression value, and electrons generated by the cathode are prevented from reaching a preset target spot; and in the second time period, the current is stopped from being supplied to the cathode, and meanwhile, the potential difference between the control electrode and the cathode is controlled to reach a guide value, so that electrons emitted by the cathode through waste heat reach the preset target spot and interact with target particles. Cathode heating is controlled in an intermittent energization mode, and accurate extraction of the low-energy scattered electron beam is achieved.

[Problem] To provide novel technology. [Solution] One aspect of the present invention provides a thermionic cathode. The thermionic cathode includes an electron source and a plurality of grids. The electron source is configured to emit electrons when heated. The plurality of grids have through-holes that allow electrons emitted from the electron source to pass in a predetermined direction. At least one of the grids is configured to reduce the movement speed of the electrons.

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 electron source is provided with: an electron emission unit containing an alloy of iridium and a rare earth element; a support part made of metal; and a joining part that joins the electron emission part and the support part. The bonding portion has a coating layer containing iridium and the metal in the support portion, and the coating layer contains iridium and the metal in the support portion.

To provide an electron source comprising an insulating base, a pair of conductive terminals, an insulating support member, a drift separation member, an emitter-cathode, and one or more heating elements.SOLUTION: Conductive terminals are exposed from a first surface of an insulating base. An insulating support member extends from the first surface of the insulating base. A drift isolation member is disposed at an end of the insulating support member remote from the insulating base. An emitter-cathode is coupled to the drift isolation member. One or more heating elements are coupled to the conductive terminals and the drift isolation member. Combination of the drift isolation member with the insulating support member can prevent stress-induced drift from impacting a position of the emitter-cathode, thereby improving mechanical stability of the electron source.SELECTED DRAWING: Figure 1A

This emitter comprises: an insulator; a pair of conductive terminals attached to the insulator and spaced apart from each other; a heater that is arranged between the tip sections of the pair of insulator terminals and emits heat as a result of being energized; an electron source formed from a first material that is heated by the heater and releases electrons; a Wehnelt electrode that has an inner surface forming an interior space together with the surface of the insulator, and that serves to apply bias voltage between said Wehnelt electrode and the electron source; and a shielding member covering part of the surface of the insulator within the interior space.

A cathode device with an electrical contact junction that operates cooler and has more stable electrical resistance than prior art Provision of. The cathode device includes an emitter tip (16) for generating electrons. It includes an elongated heater (14) having a proximal end and a distal end. The emitter tip can be located at the distal end of the heater. Two spaced-apart legs (15a, 15b) extend away from the heater's distal end and terminate at the proximal end, forming an elongated slot therebetween. Two electrical contacts (20) compressively engage opposite outer surfaces of the two legs at the heater's proximal end to mechanically secure and electrically connect the two legs to their respective electrical contacts at a junction located away from the emitter tip to maintain a lower junction temperature.

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.

According to the cathode structure of the ionizer, a large arc structure formed by winding one metal hot wire in the prior art is changed into a small arc structure formed by winding two metal hot wires, the pins are arranged at the two ends of each metal hot wire, and the metal hot wires are fixed to the sheet electrodes through the pins, so that the cathode structure of the ionizer is formed. According to the metal hot wire, the first end of the sheet-shaped electrode is provided with a pin positioning groove or an arc-shaped surface and a limiting step, so that the original multi-point welding between the linear pin and the sheet-shaped electrode is changed into straight welding, the angular tensile stress during welding is reduced, the metal hot wire is not prone to deformation in the assembling process, and the concentricity of the metal hot wire and other electrodes is kept; the stability of a small arc structure formed after welding is improved, a welding area of the metal hot wire and the sheet electrode is far away from a high-temperature area of the metal hot wire by arranging the linear pins, an effective electron emission area is enlarged, and heat loss generated by heat conduction is reduced. The efficiency of the metal heating wire is remarkably improved, the metal heating wire is not prone to fusing failure, and the service life 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 embodiment of the present invention discloses a cathode thermal subassembly for a klystron electron gun, comprising: a cathode base; a cathode disposed on the top of the cathode base; a thermal subassembly located in the cathode base; a heat shield fixed in the cathode base, the heat shield being disposed below the thermal subassembly; and a cathode base disposed at the bottom of the cathode base, the cathode base being configured to reduce the heat conduction of the thermal subassembly; the cathode base being a basket-shaped structure, comprising a first ring body, a second ring body, and a plurality of support rods disposed between the first ring body and the second ring body, the two ends of the support rods being respectively fixed to the first ring body and the second ring body; the first ring body and the second ring body being disposed in parallel and concentrically. By designing the cathode base at the connection between the electron gun cathode thermal subassembly and the klystron cavity structure into a basket-shaped structure, heat conduction is effectively reduced, the stability of the electron gun is improved, and the life of the klystron is extended.

The present invention relates to an electron gun cathode mount adapted at one end to secure a thermionic cathode and at the other end to be connected to an attachment member, wherein the electron gun cathode mount is structured so as to be capable of, when in use, reducing heat transfer from the thermionic cathode to the attachment member, and the material forming the electron gun cathode mount has a thermal conductivity of less than 10 Wm−1K−1 at the operating temperature of the thermionic cathode in a direction from the thermionic cathode to the attachment member. The present invention also relates to an electron gun assembly having the electron gun cathode mount installed therein.

An emitter includes an insulator, a pair of terminals attached to the insulator separately from each other, at least one filament attached between the pair of terminals in an arch shape, and an electron source fixed to the filament. The filament has bent portions between a contact with respect to the electron source and contacts with respect to the terminals. A device is provided with the emitter.

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.

An ion source for forming a plasma includes a cathode having a cavity and a cathode surface defining a cathode step. A filament is disposed within the cavity, and a cathode shield has a cathode shield surface at least partially surrounding the cathode surface. A cathode gap is defined between the cathode surface and the cathode shield surface, and the cathode gap defines a tortuous path for restricting movement of the plasma through the gap. The cathode surface may have a stepped cylindrical surface defined by a first cathode diameter and a second cathode diameter. The first cathode diameter and the second cathode diameter are different from each other to define the cathode step. The stepped cylindrical surface may be an outer surface or an inner surface. The first cathode diameter and the second cathode diameter may be concentric or axially offset.

The invention belongs to the technical field of electron flow emitting devices, and particularly relates to a device for enhancing electron emission guidance quality, which comprises a base, a guide piece column and at least one lamp filament, each pair of conductive columns penetrate through the base and are electrically connected with a power supply, and the lamp filament is electrically connected with the conductive columns. The conductive column is fixedly installed on the base, the lamp filament is installed on the base, the insulating parts are arranged at the two ends of the connecting position of the conductive column and the base respectively and wrap the conductive column, and the guiding part is fixedly installed on the base and located behind the lamp filament so that the situation that electrons emitted by the lamp filament thermally flow to a non-working area to be dissipated can be reduced. The density of the electron flow is controlled, the use of multiple working areas is met, and the dissipation direction of the electron flow can be controlled through the guide piece.

The X-ray tube includes: a housing; the electron gun emits electron beams in the box body; and a target that generates X-rays by the incidence of the electron beam within the housing. The electron gun includes: a cathode emitting electrons; and a focusing electrode that focuses the electrons as electron beams on the target. The focusing electrode has a cylindrical shape having an inner surface and an outer surface. The inner surface has a first region and a second region located on the target side with respect to the first region. The average roughness of the second region is smaller than the average roughness of the first region.

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.

Various methods and systems are provided for an emitter assembly for a cathode of an X-ray tube. In one example, an emitter assembly comprises a first end of a substantially flat emitter supported by two rods extending from a two-rod insulator assembly, and a second end of the substantially flat emitter supported by a compliant, single rod insulator 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

To provide an electron source with an excellent position stability of an electron source chip in use, and provide a manufacturing method of the same.SOLUTION: An emitter includes: an electron source chip; a first filament connected to a first position of a side surface of the electron source chip; a second filament that is connected to a second position of the side surface of the electron source chip; two upper part positive terminals to which two first side surfaces of the first filament are connected, respectively; two upper part negative terminals to which two second side surfaces of the second filament are connected, respectively; one lower part positive terminal that is electrically connected to the two upper part positive terminals; one lower part negative terminal that is electrically connected to the two upper part negative terminals; and an insulator that carriers the upper part positive terminal, the upper part negative terminal, the lower part positive terminal, and the lower part negative terminal. The first position and the second position are different from each other. The first side surfaces of the first filament are connected to the side surfaces of the upper part positive terminals respectively, and the second side surfaces of the second filament are connected to the side surfaces of the upper part negative terminals respectively.SELECTED DRAWING: Figure 1

An emitter (1) having: an electron source tip (10); a first filament (50) connected to a first position (10a) on the side surface of the electron source tip (10); a second filament (60) connected to a second position (10b) on the side surface of the electron source tip (10); two upper positive terminals (20a, b) connected to first side surfaces (50a, b) at two locations of the first filament (50), respectively; two upper negative terminals (20c, d) connected to second side surfaces (60a, b) at two locations of the second filament (60), respectively; one lower positive terminal (30a) electrically connected to the two upper positive terminals (20a, b); one lower negative terminal (30b) electrically connected to the two upper negative terminals (20c, d); and an insulator (40) carrying the upper positive terminals (20a, b), the upper negative terminals (20c, d), the lower positive terminal (30a), and the lower negative terminal (30b), the first position (10a) and the second position (10b) being different positions, the first side surfaces (50a, b) of the first filament (50) being connected to the side surfaces of the upper positive terminals (20a, b), respectively, and the second side surfaces (50a, b) being connected to the side surfaces of the lower positive terminals (30a, b). The second side surfaces (60a, b) of the second filament (60) are connected to the side surfaces of the upper negative terminals (20c, d), respectively.

The present invention relates to an annular cathode for a vacuum tube, which comprises: - a cylindrical central support (7) whose axis is the axis of the cathode; - an outer peripheral electron emitter (6) with an annular cross-section extending above the outer periphery of the cathode, the axis of the electron emitter (6) being the axis of the cathode; and, - a folded skirt (4) which is fixed to the central support (7) at its inner end and is fixed to a plurality of lugs (5) at its outer end; - each lug (5) is arranged in series with the folded skirt (4) and is fixed to the folded skirt (4) and to the inner surface of the electron emitter (6).