Cathode heater assembly for klystron electron gun

Abstract

The utility model discloses a kind of cathode heater subassemblies for klystron electron gun, it is characterized in that, including: cathode base, heater sleeve, heater and detachable heat shield assembly, the upper and lower two end surfaces of cathode base are respectively provided with emitting surface and mounting groove, heater sleeve is detachably fixed in mounting groove, and the end surface of heater sleeve back to cathode base is equipped with accommodating groove;Heater is installed in accommodating groove, and the part of heater in accommodating groove is wrapped with insulating layer;Heat shield assembly includes outer heat shield and inner heat shield, outer heat shield is sleeved in cathode base, and inner heat shield is installed in outer heat shield and covers heater sleeve and heater.The utility model can realize reversibility dismounting and maintenance, and heater material volatilization can be avoided directly deposited on the emitting surface of cathode base, help to maintain the emitting surface cleanliness of cathode base, to improve electron emission efficiency, high-temperature solder can also be reduced in use, reduce cost.

Description

Technical Field

[0001] This utility model relates to the field of klystron technology, and in particular to a cathode thermal assembly for a klystron electron gun. Background Technology

[0002] As a core component of high-power microwave devices, the reliability of the electron gun cathode-thermal assembly of the klystron directly affects the overall performance of the tube.

[0003] Traditional cathode and heat source assemblies generally adopt an integrated welding structure. For example, the welding method of a cathode and heat source assembly for a high-power klystron electron gun disclosed in application publication number CN107275169A involves first brazing an inner heat shield sleeve to the cathode with high-temperature solder, then fixing the wound heat source to the inner heat shield sleeve on the bottom surface of the cathode with paste alumina, and then assembling other upper and lower heat shields, outer heat shield sleeves, and connecting chassis. Finally, the cathode and heat source assembly is brazed with high-temperature solder in a high-temperature hydrogen furnace. During the high-temperature welding, the paste alumina is sintered into solid alumina ceramic, which firmly fixes the heat source and forms the cathode and heat source assembly.

[0004] Alumina ceramic possesses functional properties such as insulation, thermal conductivity, and high-temperature resistance for heat exchangers. However, the forming and quality control of alumina in the high-temperature sintered integrated cathode-heater assembly are difficult, potentially leading to heat exchanger powder shedding. Furthermore, if the cathode or heater is damaged after assembly, or if material replacement is desired, separation is difficult, requiring reassembly, especially for klystrons where this operation is costly during the testing phase. Additionally, with the heater directly fixed to the cathode, volatiles from the heater material can directly deposit on the cathode surface during high-temperature brazing, easily causing cathode surface contamination. Therefore, it is necessary to improve the existing technology to overcome its shortcomings. Utility Model Content

[0005] The problem to be solved by this utility model is to provide a cathode thermal assembly for a klystron electron gun, so as to overcome the defects of existing cathode thermal assemblies that adopt an integrated welded structure, which easily causes cathode surface contamination and high cost due to the inability to disassemble and replace parts.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a cathode thermal assembly for a klystron electron gun, comprising:

[0007] A cathode substrate, wherein the upper and lower end faces of the cathode substrate are respectively provided with an emitting surface and a mounting groove;

[0008] A heat sleeve is detachably fixed in the mounting groove, and the end face of the heat sleeve facing away from the cathode substrate is provided with a receiving groove;

[0009] The heat element is installed in the receiving groove, and the part of the heat element in the receiving groove is wrapped with an insulating layer;

[0010] And a detachable heat shield assembly, the heat shield assembly including an outer heat shield and an inner heat shield, the outer heat shield being fitted onto the cathode substrate, and the inner heat shield being installed inside the outer heat shield and covering the heat element sleeve and the heat element.

[0011] As a further improvement of this utility model, the inner peripheral wall of the mounting groove is provided with an internal thread, the outer peripheral wall of the heat sleeve is provided with an external thread, and the heat sleeve is screwed into the mounting groove by a threaded connection.

[0012] As a further improvement of this utility model, a gap is left between the internal thread and the external thread, and a heat-conducting pad is provided in the gap.

[0013] As a further improvement of this utility model, the external heat shield and the cathode substrate, as well as the internal heat shield and the external heat shield, can be detachably connected.

[0014] As a further improvement of this utility model, the outer circumference of the cathode substrate is provided with a plurality of threaded holes, and the outer heat shield is provided with a plurality of through holes that are the same number as the threaded holes and correspond one-to-one, and each of the through holes is fitted with a screw that locks into the threaded hole.

[0015] As a further improvement of this utility model, the outer heat shield is cylindrical and has an annular groove along its inner wall; the inner heat shield is sheet-shaped and its outer edge is engaged in the annular groove.

[0016] As a further improvement of this utility model, the heat source is a ring-shaped double helix structure made of a tungsten rhenium wire, and one end of the heat source is led out through the inner heat screen.

[0017] As a further improvement of this utility model, the middle part of the heat sleeve is provided with a solder groove, and the other end of the heat element is bent into a hook shape and extends into the solder groove. The other end of the heat element and the heat sleeve are welded and fixed together by the solder in the solder groove.

[0018] As a further improvement of this utility model, the shape of the heat sleeve is similar to that of the mounting groove, so that the outer surface of the heat sleeve can be tightly attached to the inner wall of the mounting groove; wherein, the heat sleeve is made of molybdenum.

[0019] As a further improvement of this utility model, the insulating layer is formed by filling the receiving groove with alumina paste and then sintering it.

[0020] The beneficial effects of this utility model are as follows: This utility model provides a cathode and thermoelectric assembly for a klystron electron gun. By installing the thermoelectric element in the receiving groove of the thermoelectric sleeve, and the thermoelectric sleeve being detachably fixed to the cathode substrate, and the thermal shield assembly being detachable, this split-type cathode and thermoelectric assembly can be easily disassembled and replaced with new parts when any part of the thermoelectric element or the cathode substrate is damaged, without the need to reassemble the entire assembly. Especially during the testing phase of the klystron by technicians to cope with different usage scenarios, it can greatly reduce operating costs, improve the utilization efficiency of the cathode substrate, thermoelectric element and thermal shield assembly, and accelerate the testing progress of the test piece. Furthermore, since the heat source and cathode substrate in this invention adopt a separate structure, high-temperature conditions are only used in the process of sintering to form the insulating layer during the entire production process of the cathode heat source assembly. The cathode substrate does not participate in this high-temperature sintering process and does not require high-temperature welding. Therefore, not only can reversible disassembly and maintenance be achieved, but also the direct deposition of heat source material volatiles on the emission surface of the cathode substrate can be avoided, which helps to maintain the cleanliness of the emission surface of the cathode substrate, thereby improving electron emission efficiency. It can also reduce the use of high-temperature solder and further reduce costs. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a perspective view of the cathode heat source assembly for the klystron electron gun of this utility model;

[0023] Figure 2 This is a cross-sectional view of the cathode heat source assembly for the klystron electron gun of this utility model;

[0024] Figure 3 This is an exploded view of the cathode heat source assembly for the klystron electron gun of this utility model;

[0025] Figure 4 A perspective view of the heatsink sleeve and heatsink of the cathode heatsink assembly for the klystron electron gun of this utility model.

[0026] Figure 5 This is a perspective view of the heat source of the cathode heat source assembly for the klystron electron gun of this utility model;

[0027] Figure 6 This is a perspective view of the external heat shield of the cathode heat source assembly for the klystron electron gun of this utility model.

[0028] Referring to the accompanying drawings, the following explanations are provided:

[0029] 1. Cathode substrate; 101. Emitting surface; 102. Mounting groove; 1021. Internal thread; 103. Threaded hole; 2. Heater sleeve; 201. Receiving groove; 202. Solder groove; 203. External thread; 3. Heater; 301. First end; 302. Second end; 4. External heat shield; 401. Through hole; 402. Annular groove; 5. Internal heat shield. Detailed Implementation

[0030] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0031] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0033] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0034] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0035] The technical solutions provided by the various embodiments of this application are described below with reference to the accompanying drawings.

[0036] See Figures 1 to 6 This utility model provides a cathode and heat source assembly for a klystron electron gun, comprising: a cathode substrate 1, a heat source sleeve 2, a heat source 3, and a detachable heat shield assembly.

[0037] In this invention, the cathode substrate 1 is cylindrical and is a tungsten sponge used to fill the emission salt. The upper end face of the cathode substrate 1 is designated as the emission surface 101, which is a concave spherical cap shape. The lower end face of the cathode substrate 1 is provided with a mounting groove 102, and the heat sink sleeve 2 is detachably fixed in the mounting groove 102. The end face of the heat sink sleeve 2 facing away from the cathode substrate 1 is provided with a receiving groove 201.

[0038] Furthermore, the heat element 3 is installed in the receiving groove 201 of the heat element sleeve 2, with both ends of the heat element 3 extending out of the receiving groove 201, while the part of the heat element 3 inside the receiving groove 201 is covered with an insulating layer to ensure that the part of the heat element 3 inside the receiving groove 201 is insulated from the heat element sleeve 2.

[0039] The insulating layer, not shown in the figure, is made of ceramic material. It is formed by filling the receiving groove 201 with alumina paste and sintering it at high temperature. The sintered insulating layer can also reliably fix the heat source 3 and the heat source sleeve 2.

[0040] Furthermore, the heat shield assembly includes an outer heat shield 4 and an inner heat shield 5. The outer heat shield 4 is fitted onto the cathode substrate 1, and the inner heat shield 5 is installed inside the outer heat shield 4 and covers the heat element sleeve 2 and the heat element 3, so that the heat element 3 is blocked by the inner heat shield 5. The closed structure formed by the inner heat shield 5 and the heat element sleeve 2 can effectively prevent alumina powder from falling into the klysonic tube chamber.

[0041] This invention innovatively designs a heatsink sleeve 2, in which the heatsink 3 is installed within the receiving groove 201 of the heatsink sleeve 2. The heatsink sleeve 2 is detachably fixed to the cathode substrate 1, and the heat shield assembly is also detachable. When any part of the heatsink 3 or the cathode substrate 1 is damaged, this split-type cathode-heatsink assembly can be easily disassembled and replaced with a new part in a timely manner without reassembling the entire assembly. Especially during the testing phase of klystrons by technicians to cope with different usage scenarios, it can greatly reduce operating costs, improve the utilization efficiency of the cathode substrate 1, the heatsink 3, and the heat shield assembly, and accelerate the testing progress of the test pieces.

[0042] Furthermore, since the heat source 3 and the cathode substrate 1 in this invention adopt a separate structure, high-temperature conditions are only used in the process of sintering to form the insulating layer during the entire production process of the cathode heat source assembly. The cathode substrate 1 does not participate in the high-temperature sintering process and does not need to be welded at high temperature. Therefore, not only can reversible disassembly and maintenance be achieved, but also the volatiles of the heat source 3 material can be prevented from being directly deposited on the emitting surface 101 of the cathode substrate 1, which helps to maintain the cleanliness of the emitting surface 101 of the cathode substrate 1, thereby improving the electron emission efficiency. It can also reduce the use of high-temperature solder and further reduce costs.

[0043] In this embodiment, the heat sleeve 2 and the cathode substrate 1 are detachable by means of a threaded connection.

[0044] See Figure 2 and Figure 3 The inner circumferential wall of the mounting groove 102 is provided with an internal thread 1021, and the outer circumferential wall of the heat sleeve 2 is provided with an external thread 203. The external thread 203 of the heat sleeve 2 is screwed onto the internal thread 1021 of the mounting groove 102, thereby realizing the fixed installation of the heat sleeve 2 and the cathode substrate 1.

[0045] Considering that there is a difference in thermal expansion between the cathode substrate 1 and the heat sink 2 when the heat sink 3 is working, which may lead to a loose fit, this utility model leaves a gap between the internal thread 1021 and the external thread 203 and provides a thermally conductive pad (not shown in the figure) in the gap. This can not only ensure thermal contact between the heat sink 2 and the cathode substrate 1, but also compensate for the difference in axial thermal expansion between the two, and reduce material degradation caused by thermal stress.

[0046] Preferably, the gap width between the internal thread 1021 and the external thread 203 is 0.1mm, and the material of the thermal pad can be graphene.

[0047] It is worth mentioning that the external heat shield 4 and the cathode substrate 1, as well as the internal heat shield 5 and the external heat shield 4, can be detachably connected in this utility model.

[0048] Continue reading Figure 2 and Figure 3 The cathode substrate 1 has a plurality of threaded holes 103 (e.g., M2 specification) arranged in a ring around its outer periphery near its upper edge. The outer heat shield 4 has a plurality of through holes 401, the same number as the threaded holes 103. When the upper end of the outer heat shield 4 is fitted onto the cathode substrate 1, the plurality of through holes 401 correspond one-to-one with the plurality of threaded holes 103. Each through hole 401 of the outer heat shield 4 is fitted with a screw that locks into the threaded hole 103. The screw fixing between the cathode substrate 1 and the heat sink sleeve 2 enables quick assembly and disassembly, improving the assembly efficiency of the cathode heat sink assembly.

[0049] like Figure 3As shown, in this embodiment, the internal heating screen 5 is a circular molybdenum sheet, and multiple internal heating screens 5 are arranged vertically at intervals.

[0050] like Figure 6 As shown, the external heat shield 4 in this embodiment is a cylindrical shape with open top and bottom ends, which can be made by spot welding a rectangular molybdenum-rhenium alloy sheet using a cylindrical oxygen-free copper mold fixture.

[0051] The outer heat shield 4 has multiple annular grooves 402 along its inner wall, and the outer edges of multiple inner heat shields 5 are correspondingly engaged in the multiple annular grooves 402. The inner heat shields 5, made of molybdenum sheet, have a certain elastic deformation capability. During assembly, the inner heat shield 5 can be directly pushed into the outer heat shield 4 from one end. Under the size limitation of the outer heat shield 4, the inner heat shield 5 is deformed by external force until it is engaged in the annular grooves 402. This method not only realizes the detachable connection between the inner heat shield 5 and the outer heat shield 4, but also makes assembly convenient and quick.

[0052] like Figure 5 As shown, the heat source 3 is a double-helix structure formed by bidirectional winding of a tungsten rhenium wire along the middle. The receiving groove 201 of the heat source sleeve 2 is annular, and the annular main body of the heat source 3 is housed in the receiving groove 201. The two ends of the heat source 3 are the first end 301 and the second end 302, respectively. The first end 301 passes through the inner heat screen 5 axially, is bent radially and extends to the middle of the cathode heat source assembly, and is then bent axially and led outward.

[0053] See Figure 4 The heat sleeve 2 has an annular boss in the middle and a solder groove 202 is formed inside the annular boss. The second end 302 of the heat element 3 is bent into a hook shape and extends into the solder groove 202. The second end 302 of the heat element 3 and the heat sleeve 2 are welded and fixed together by the solder in the solder groove 202, so as to realize the electrical connection between the heat element 3 and the heat sleeve 2 and facilitate the connection of the second end 302 of the heat element 3 to the circuit.

[0054] See Figure 2 The shape of the heat sleeve 2 is similar to that of the mounting groove 102. When the heat sleeve 2 is assembled in the mounting groove 102, the outer surface of the heat sleeve 2 can be tightly attached to the inner wall of the mounting groove 102, ensuring a tight fit between the two, that is, ensuring thermal contact between the two and the stability of the overall structure.

[0055] In this embodiment, the heat sleeve 2 is made of molybdenum material that is resistant to high temperatures and has a low coefficient of thermal expansion.

[0056] The manufacturing process of the cathode heat source assembly for the klystron electron gun of this utility model is as follows:

[0057] First, alumina paste is filled into the receiving groove 201 of the heat element sleeve 2, and the heat element 3, which is wound into a double helix structure, is embedded in the alumina paste. After high-temperature sintering, an insulating layer is formed around the heat element 3, and the heat element 3, the insulating layer and the heat element sleeve 2 are combined into one.

[0058] Next, the cathode substrate 1 is subjected to a "salt immersion" treatment and then screwed tightly onto the heat sleeve 2 of the above-mentioned integrated structure; during the screwing process, a heat-conducting pad is installed in the gap between the internal thread 1021 of the cathode substrate 1 and the external thread 203 of the heat sleeve 2.

[0059] Then, the thermal screen assembly and the cathode substrate 1 are fixed with screws to form a cathode thermal assembly for a klystron electron gun.

[0060] Since high-temperature conditions are only used in the process of sintering to form the insulating layer, and the cathode substrate 1 does not participate in the high-temperature sintering process and does not need to be welded at high temperature, if the cathode substrate 1 or the heat element 3 experiences a short circuit or open circuit during the test, the heat shield assembly can be disassembled and the cathode substrate 1 or the heat element 3 can be replaced without scrapping the entire cathode heat element assembly, thus achieving reversible disassembly and repair.

[0061] Furthermore, by adopting a split structure design, this utility model avoids technical problems such as damage to the sintered thermal structure caused by the inconsistency between the alumina sintering temperature and the "salt immersion" temperature of the cathode substrate 1. At the same time, it can prevent the volatiles of the thermal material 3 from being directly deposited on the emitting surface 101 of the cathode substrate 1, which helps to maintain the cleanliness of the emitting surface 101 of the cathode substrate 1.

[0062] It is evident that the fabrication process of the klystron electron gun cathode thermal assemblies of this invention is relatively simple, requiring no complex experimental equipment or strict experimental conditions, thus providing a new technical path for the fabrication of klystron cathode thermal assemblies.

[0063] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A cathode thermal assembly for a klystron electron gun, characterized in that, include: The cathode substrate (1) has an emitting surface (101) and a mounting groove (102) on its upper and lower end faces, respectively. A heat sleeve (2) is detachably fixed in the mounting groove (102), and the heat sleeve (2) has a receiving groove (201) on one end face opposite to the cathode substrate (1). The heat element (3) is installed in the receiving groove (201), and the part of the heat element (3) in the receiving groove (201) is covered with an insulating layer; And a detachable heat shield assembly, the heat shield assembly including an outer heat shield (4) and an inner heat shield (5), the outer heat shield (4) being fitted onto the cathode substrate (1), the inner heat shield (5) being installed inside the outer heat shield (4) and covering the heat element sleeve (2) and the heat element (3).

2. The cathode thermal assembly for a klystron electron gun according to claim 1, characterized in that: The inner peripheral wall of the mounting groove (102) is provided with an internal thread (1021), and the outer peripheral wall of the heat sleeve (2) is provided with an external thread (203). The heat sleeve (2) is screwed into the mounting groove (102) by a threaded connection.

3. The cathode thermal assembly for a klystron electron gun according to claim 2, characterized in that: A gap is left between the internal thread (1021) and the external thread (203), and a heat-conducting pad is provided in the gap.

4. The cathode thermal assembly for a klystron electron gun according to claim 1, characterized in that: The external heat shield (4) and the cathode substrate (1) are detachably connected, as are the internal heat shield (5) and the external heat shield (4).

5. The cathode thermal assembly for a klystron electron gun according to claim 4, characterized in that: The outer circumference of the cathode substrate (1) is provided with a plurality of threaded holes (103), and the outer heat shield (4) is provided with a plurality of through holes (401) that are the same number as the threaded holes (103) and correspond one-to-one. Each through hole (401) is fitted with a screw that is locked to the threaded hole (103).

6. The cathode thermal assembly for a klystron electron gun according to claim 4, characterized in that: The outer heat shield (4) is cylindrical and has an annular groove (402) along its inner wall; the inner heat shield (5) is sheet-shaped and its outer edge is engaged in the annular groove (402).

7. The cathode thermal assembly for a klystron electron gun according to claim 1, characterized in that: The heat source (3) is a ring-shaped double helix structure made of a tungsten rhenium wire, and one end of the heat source (3) is led out through the inner heat screen (5).

8. The cathode thermal assembly for a klystron electron gun according to claim 7, characterized in that: The heat sleeve (2) is provided with a solder groove (202) in the middle. The other end of the heat element (3) is bent into a hook shape and extends into the solder groove (202). The other end of the heat element (3) is welded and fixed to the heat sleeve (2) by the solder in the solder groove (202).

9. The cathode thermal assembly for a klystron electron gun according to claim 1, characterized in that: The heat sleeve (2) is similar in shape to the mounting groove (102) so that the outer surface of the heat sleeve (2) can be tightly attached to the inner wall of the mounting groove (102); wherein the heat sleeve (2) is made of molybdenum.

10. The cathode thermal assembly for a klystron electron gun according to claim 1, characterized in that: The insulating layer is formed by sintering aluminum oxide paste filled in the receiving groove (201).

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