A target structure and acceleration tube assembly

Abstract

The application discloses a target structure and an accelerating tube, relates to the technical field of medical equipment, and aims to solve the technical problem that cracks are prone to occurring in a ray target, leading to vacuum failure of the accelerating tube. The target structure comprises a target, an oxidation-resistant layer and a sealing element. The sealing element is a hollow cylindrical structure with one end being closed and the other end being open, is arranged above the target, and is arranged close to the target at the open end of the sealing element and used for sealing the target. The oxidation-resistant layer is arranged on the surface of the side of the target bombarded by an electron beam. The oxidation resistance and ductility of the material of the oxidation-resistant layer are higher than those of the material of the target.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and more particularly to a target structure and an acceleration tube assembly. Background Technology

[0002] Medical linear accelerators use microwave electric fields to accelerate electrons to higher energies in a straight line. The accelerator tube is filled with a microwave electric field. When electrons are emitted from the electron gun and enter the accelerator tube, they are continuously accelerated under the influence of the microwave electric field, gaining sufficient energy. The accelerated high-energy electron beam is then guided to a radiation target. When the high-energy electrons collide with the radiation target, they suddenly decelerate, producing high-energy photons, or X-rays, according to electromagnetic radiation theory. These X-rays are then adjusted by components such as collimators and homogenizers to form a therapeutic beam for precise irradiation of tumors.

[0003] To ensure electrons are accelerated to the high-energy state required for treatment, the accelerator tube is designed as a vacuum environment. This prevents frequent collisions between electrons and gas molecules during acceleration, thus avoiding energy loss. In this technology, the radiation target and the accelerator tube are welded together, with the radiation target acting as a seal for the accelerator tube.

[0004] However, since a large amount of heat is generated when the electron beam collides with the X-ray target to produce X-rays, there is usually only a 1% conversion rate, with the remaining 99% of the energy being converted into heat. This heat accumulates on the X-ray target, causing thermal stress to concentrate on the target, which leads to frequent cracking of the target, and in turn, causes vacuum failure of the accelerator tube, resulting in equipment shutdown. Utility Model Content

[0005] The purpose of this application is to provide a target structure and an accelerator tube assembly to solve the technical problem that cracks easily appear in the X-ray target, leading to vacuum failure of the accelerator tube.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] In a first aspect, this application provides a target structure, including a target, an anti-oxidation layer, and a sealing element; the sealing element is a hollow cylindrical structure with one end closed and the other end open, disposed above the target, with the open end of the sealing element disposed close to the target for sealing the target; the anti-oxidation layer is disposed on the surface of the target on the side bombarded by the electron beam; the anti-oxidation layer material has higher anti-oxidation properties and ductility than the target material.

[0008] Since the seal is a hollow cylindrical structure with one end closed and is located above the target, it seals the target and effectively prevents air and impurities from the external environment from entering the target's working area, ensuring the stability of the target's working environment and creating favorable conditions for the target's efficient operation.

[0009] Furthermore, the anti-oxidation layer is located on the surface of the target on the side bombarded by the electron beam, and the material of the anti-oxidation layer has higher oxidation resistance than the target material. Therefore, the anti-oxidation layer effectively protects the target from oxidation, significantly reducing the risk of oxidation during use, extending the target's lifespan, and improving the stability and reliability of the target structure.

[0010] Because the ductility of the antioxidant layer is higher than that of the target material, it can act as a buffer when the target is subjected to external forces. Therefore, when the target is bombarded by a particle beam, the highly ductile antioxidant layer can absorb some of the energy through its own deformation, reducing stress concentration on the target and thus protecting its structural integrity. In some embodiments of this application, the cavity formed by the hollow portion of the seal and the target is in a vacuum state.

[0011] In some embodiments of this application, the target structure further includes a gradient heat dissipation component, which surrounds the target structure and includes multiple layers of gradient heat dissipation material with progressively increasing thermal conductivity from the direction closer to the target structure to the direction farther away from the target structure.

[0012] In some embodiments of this application, the target structure further includes a heat dissipation substrate, and the target and sealing element are embedded in the heat dissipation substrate.

[0013] In some embodiments of this application, the target structure further includes a first cooling device disposed in the heat dissipation substrate at the bottom of the target for cooling the target structure.

[0014] In some embodiments of this application, the first cooling device includes a first flow channel, a second flow channel, and a third flow channel connected in sequence. The cross-sectional area of ​​the second flow channel is smaller than the cross-sectional areas of the first and third flow channels. The orthographic projection of the second flow channel on a first plane at least partially coincides with the orthographic projection of the target on the first plane. The first plane is a plane perpendicular to the arrangement direction of the target and the seal. The second flow channel is capable of heat exchange with the target.

[0015] In some embodiments of this application, the target structure further includes a second cooling device disposed within a heat dissipation substrate and surrounding the target structure for cooling the target structure.

[0016] In some embodiments of this application, the second cooling device is one or more of a cooling jacket assembly and a heat pipe assembly.

[0017] In some embodiments of this application, when the second cooling device is a cooling jacket assembly, there is a circulating cooling medium flowing inside the cooling jacket assembly; when the second cooling device is a heat pipe assembly, the heat pipe assembly includes multiple heat pipes, which are arranged along the circumference of the target and are all thermally connected to the target structure; or the heat pipe assembly includes a single heat pipe, which is arranged spirally around the target structure along the axial direction of the target structure and is thermally connected to the target structure.

[0018] In some embodiments of this application, a heat radiation film is provided on the outer surface of the heat dissipation substrate, which is used to facilitate heat exchange between the heat dissipation substrate and the outside.

[0019] In some embodiments of this application, the heat dissipation substrate includes heat dissipation fan fins, and the heat dissipation fan fins are thermally connected to the heat dissipation substrate.

[0020] Secondly, this application also provides an accelerator tube assembly, including an accelerator tube body with an electron beam outlet and a target structure described in the first aspect. The closed end of the sealing element of the target structure is located at the electron beam outlet of the accelerator tube body to seal the accelerator tube body and maintain it in a vacuum state.

[0021] In the accelerator tube assembly provided in this application embodiment, a target structure is used to seal the accelerator tube body. First, the vacuum cavity of the accelerator tube body and the target are isolated by the sealing element of the target structure. Even if the target develops cracks / microcracks due to electron beam bombardment, the vacuum state of the vacuum cavity inside the accelerator tube body will not be affected. Second, because the anti-oxidation layer of the target structure has high ductility, when the target is bombarded by the electron beam, the target may develop microcracks, but the anti-oxidation layer will not develop microcracks due to its high ductility. Even if the sealing element is damaged / cracked at the location bombarded by the electron beam, the anti-oxidation layer can still maintain the vacuum state of the accelerator tube body, thereby extending the service life of the accelerator tube assembly. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of 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.

[0023] Figure 1 This is one of the schematic diagrams of a target structure provided in an embodiment of this application;

[0024] Figure 2 This is a second schematic diagram of a target structure provided in an embodiment of this application;

[0025] Figure 3 A cross-sectional view of a first cooling device provided in an embodiment of this application;

[0026] Figure 4 This is a cross-sectional view of a target structure provided in an embodiment of this application.

[0027] Figure label:

[0028] 1000-Accelerator Tube Assembly;

[0029] 100 - Target structure; 200 - Accelerator tube body; 201 - Electron beam exit; 202 - Electron beam;

[0030] 10-Target; 11-Concentrated heat zone;

[0031] 20-Antioxidant layer;

[0032] 30 - Seal; 31 - Receiving cavity; 32 - Opening;

[0033] 40 - Heat dissipation substrate;

[0034] 50 - First cooling device; 51 - First flow channel; 52 - Second flow channel; 53 - Third flow channel;

[0035] 60 - Second cooling device; 61 - Heat pipe;

[0036] 70-Heat radiation film;

[0037] 80 - Heat dissipation fan fins. Detailed Implementation

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0040] The terms "first" and "second," etc., used in the specification and drawings of this application are used to distinguish different objects or to distinguish different treatments of the same object, rather than to describe a specific order of objects.

[0041] Furthermore, the terms "comprising" and "having," and any variations thereof, used in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include other steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0042] It should be noted that in the embodiments of this application, the words "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0043] In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0044] First, for ease of understanding, the terms used in this application will be explained.

[0045] A target (also known as a radiation target) is a component in a radiation-generating device that interacts with high-speed particles (such as electrons and ions) to produce specific types of radiation (such as X-rays and gamma rays). When high-speed particles bombard a radiation target, the atoms of the target material are excited, and their inner-shell electrons transition to higher energy levels. Subsequently, outer-shell electrons transition to inner-shell electrons to fill the vacancies, and the excess energy is released as photons, forming radiation. Different target materials and particle bombardment conditions will produce radiation with different energies and characteristics. The material, structure, and performance of the radiation target directly affect the intensity, energy distribution, and radiation characteristics of the radiation.

[0046] Accelerator tubes typically consist of electrodes, a focusing system, and a vacuum system. The electrodes apply a specific electric field to provide acceleration to charged particles, enabling them to achieve higher speeds and energies. The focusing system ensures that the particle beam maintains minimal divergence during acceleration, preserving beam stability and directionality. The vacuum system reduces collisions between particles and gas molecules during acceleration, minimizing energy loss and ensuring optimal acceleration. Accelerator tubes can be categorized into traveling-wave and standing-wave types based on their acceleration principles. In medical linear accelerators, accelerator tubes accelerate electrons to high-energy states for use in radiotherapy of tumors.

[0047] An accelerator is a device that uses electric and magnetic fields to give charged particles higher energy. It includes a particle source, an acceleration system, a beam transport system, a vacuum system, and a control system. The particle source generates initial charged particles, the acceleration system (such as an accelerator tube) accelerates the particles, the beam transport system guides and controls the trajectory of the particle beam, the vacuum system ensures that the particles are not disturbed by gas during acceleration, and the control system precisely regulates the operating state of each part of the accelerator. Accelerators can accelerate particles to near the speed of light, producing high-energy particle beams or rays.

[0048] Because electrons accelerated to a high-energy state have stronger penetrating power, they can penetrate deep into the human body, reaching tumors located in deeper areas to effectively irradiate them, achieving precise targeting and improving treatment outcomes. To ensure that electrons are accelerated to the high-energy state required for treatment, the accelerator tube is set up in a vacuum environment. This avoids frequent collisions between electrons and gas molecules during acceleration, preventing energy loss.

[0049] In related technologies, the X-ray target and the accelerator tube are welded together, with the X-ray target acting as a seal for the accelerator tube body. However, because a large amount of heat is generated when the electron beam collides with the X-ray target to produce X-rays, typically only 1% of the energy is converted into heat, with the remaining 99% being converted into heat. This heat accumulates on the X-ray target, causing thermal stress concentration and frequent cracking of the target. This, in turn, leads to the failure of the vacuum environment within the accelerator tube's vacuum chamber, resulting in a shorter accelerator lifespan and higher maintenance costs.

[0050] Based on this, in a first aspect, embodiments of this application provide a target structure. Figure 1 A schematic diagram of a target structure according to an embodiment of this application is shown. Please refer to [link / reference]. Figure 1 The target structure 100 includes: a target 10, an antioxidant layer 20, and a sealant 30.

[0051] The sealing element 30 is a hollow cylindrical structure with one end closed and the other end open, and is disposed above the target 10. The open end of the sealing element 30 is disposed close to the target 10, and the closed end is disposed away from the target 10. The sealing element 30 is used to seal the target 10.

[0052] An antioxidant layer 20 is disposed on the surface of the target 10 on the side bombarded by the electron beam 202. The antioxidant layer 20 has higher antioxidant properties and ductility than the target 10. That is, the antioxidant layer 20 is disposed on the surface of the target 10 facing the seal 30.

[0053] like Figure 1 As shown, the cross-section of the seal 30 can be an inverted "U" shape. For example, the seal 30 has a receiving cavity 31 and an open end 32 communicating with the receiving cavity 31. Optionally, the seal 30 can be provided with one or more layers; this embodiment does not limit this.

[0054] In addition, the seal 30 can be made of a low atomic number material, such as a high-temperature titanium alloy, a high-temperature copper alloy, or a high-temperature molybdenum alloy. Thus, when the electron beam 202 passes through the seal 30, electron decay is reduced, resulting in less heat generation. Under high-load output conditions of the electron beam 202, the thermal life of the seal 30 is longer.

[0055] The target 10 is used to collide with the electron beam, thereby generating high-energy rays. The target 10 can be made of tungsten alloy, and trace elements such as rhenium can be added to the tungsten alloy to improve the fatigue life of the target 10.

[0056] The anti-oxidation layer 20 has higher oxidation resistance and ductility than the target 10. Since tungsten alloys typically begin to oxidize at 400°C and transform into WO3 at temperatures above 500°C, an anti-oxidation layer is attached to the surface of the target 10 to improve its oxidation resistance and ductility. For example, the anti-oxidation layer 20 can be made of high-temperature resistant materials such as gold, iridium, or tantalum. The thickness of the anti-oxidation layer 20 can be less than or equal to 1 μm; for example, the thickness can be 1 μm, 0.7 μm, 0.5 μm, 0.4 μm, etc.

[0057] Optionally, the anti-oxidation layer 20 can be attached to the target 10 by processes such as magnetron sputtering or chemical vapor deposition. For example, a 0.5 μm thick coating can be sputtered onto the surface of the target 10 under conditions of magnetron sputtering power of 3 kW and argon pressure of 0.5 Pa. In this way, oxidation of the tungsten alloy target 10 can be suppressed at temperatures above 500°C.

[0058] In this way, the antioxidant layer 20 can make the surface of the target 10 have high antioxidant properties and ductility without affecting the bremsstrahlung effect of the target 10, thereby improving the high temperature resistance of the target 10.

[0059] The target structure provided in this application embodiment has a sealing element 30 that is a hollow cylindrical structure with one end closed and is located above the target 10. Therefore, the sealing element 30 can effectively prevent air, impurities, etc. from the external environment from entering the working area of ​​the target 10, ensuring the stability of the working environment of the target 10 and creating good conditions for the efficient operation of the target 10.

[0060] Furthermore, an anti-oxidation layer 20 is disposed on the surface of the target 10 on the side bombarded by the electron beam 202, and the material of the anti-oxidation layer 20 has higher oxidation resistance than the material of the target 10. Therefore, the provision of the anti-oxidation layer 20 can effectively protect the target 10 from oxidation, significantly reduce the risk of the target 10 being oxidized during use, extend the service life of the target 10, and improve the stability and reliability of the target structure 100.

[0061] Meanwhile, since the ductility of the anti-oxidation layer 20 is higher than that of the target 10, the anti-oxidation layer 20 can play a certain buffering role when the target 10 is subjected to external forces. Therefore, when the target 10 is bombarded by a particle beam, the ductile anti-oxidation layer 20 can absorb some of the energy through its own deformation, reduce the stress concentration on the target 10, and thus protect the structural integrity of the target 10.

[0062] In some embodiments of this application, the cavity formed by the hollow portion of the sealing member 30 of the target structure 100 and the target 10 is in a vacuum state. That is, the receiving cavity 31 is in a vacuum state.

[0063] It should be noted that during the process of the electron beam 202 passing through the seal 30 into the vacuum chamber (receptacle 31) and bombarding the target 10, the vacuum state of the receptacle 31 avoids collisions between electrons and gas molecules. Electrons can maintain high energy and a stable beam shape, ensuring that the electron beam 202 interacts with the target 10 in an optimal state, thereby producing high-quality, stable radiation. Furthermore, by setting the receptacle 31 to a vacuum state, the high temperature generated when the electron beam 202 bombards the target 10 can reduce the oxidation of the seal 30, thereby reducing electron deflection.

[0064] In some embodiments of this application, the target structure 100 further includes a gradient heat dissipation assembly. The gradient heat dissipation assembly is disposed around the target structure 100 and includes multiple layers of gradient heat dissipation material with progressively increasing thermal conductivity from near the target structure 100 to away from the target structure 100. For example, an oxygen-free copper layer, a molybdenum alloy layer, and a graphite layer may be sequentially disposed from near the target structure 100 to away from the target structure 100.

[0065] Because the gradient heat dissipation component is wrapped around the target structure 100 and consists of multiple layers of gradient heat dissipation material, with the thermal conductivity of the material increasing sequentially from the direction closest to the target structure 100 to the direction furthest away from the target structure 100, the heat dissipation material layer furthest from the target 100 can quickly transfer heat to the external environment due to its higher thermal conductivity, achieving efficient heat dissipation. Since the thermal conductivity of the multiple gradient heat dissipation material layers increases from the inside to the outside, heat can be transferred from the target 100 to the outside along a reasonable path and at a reasonable speed, forming an orderly heat dissipation process. Compared with traditional single heat dissipation materials, the gradient heat dissipation component can better match the heat dissipation needs of different parts of the target structure 100. That is, the low thermal conductivity material layer close to the target 100 will not generate thermal stress due to a sudden drop in local temperature caused by excessively rapid heat conduction when absorbing heat; while the high thermal conductivity material layer furthest from the target 100 can quickly conduct heat away, effectively preventing heat accumulation near the target structure 100, improving overall heat dissipation efficiency, alleviating thermal damage to the target 100, and extending the service life of the target 100.

[0066] Please refer to other embodiments of this application. Figure 1 The target structure 100 also includes a heat dissipation substrate 40, in which the target 10 and the sealing element 30 are embedded. The heat dissipation substrate 40 is made of a material with high thermal conductivity. For example, the material of the heat dissipation substrate 40 can be a copper alloy, a silver alloy, an aluminum alloy, etc.

[0067] In one possible structural design, the first surface of the heat dissipation substrate 40 is provided with a receiving groove, and the target 10 and the sealing member 30 are fixedly disposed in the receiving groove of the heat dissipation substrate 40.

[0068] Optionally, the seal 30 may be fixed to the heat sink substrate 40 by means including but not limited to snap-fit, threaded connection, hinge, welding, riveting, etc. For example, the seal 30 can be pressed into the heat sink substrate 40 by an interference fit to ensure reliable sealing. Furthermore, the interference fit should be designed to ensure that both the seal 30 and the heat sink substrate 40 remain in an interference fit state when thermal deformation occurs, thus ensuring the connection strength between them.

[0069] Optionally, the target 10 may also be fixed to the heat sink 40 by means of, but not limited to, snap-fit, threaded connection, hinge, welding, riveting, etc. For example, the target 10 can be press-fitted into the heat sink 40, and the periphery of the target 10 can be connected to the heat sink 40 by brazing. In this way, the connection strength between the target 10 and the heat sink 40 is high, preventing accelerator malfunction due to the target 10 falling off.

[0070] Because the heat dissipation substrate 40 is made of a high thermal conductivity material, it can efficiently transfer heat. Since the target 10 and the sealing element 30 are embedded in the heat dissipation substrate 40, when the target 10 generates heat under the bombardment of the electron beam 202, the heat is rapidly conducted to the heat dissipation substrate 40. The heat dissipation substrate 40, with its high thermal conductivity, quickly diffuses the heat to the outside (e.g., outside air), preventing heat accumulation in localized areas of the target 10 and the sealing element 30. Simultaneously, the heat dissipation substrate 40 provides a stable support structure for the target 10 and the sealing element 30, ensuring the mechanical stability of the target structure 100 during operation and preventing displacement of the target 10 and the sealing element 30 due to vibration, external forces, or other factors, thus affecting the normal operation of the equipment.

[0071] In some embodiments of this application, the target structure 100 further includes a first cooling device 50, which is disposed within the heat dissipation substrate 40 and located at the bottom of the target 10, and is used to cool the target structure 100. That is, the first cooling device 50 is disposed within the heat dissipation substrate 40 and is located on the side of the target 10 away from the sealing member 30.

[0072] Because the heat dissipation substrate 40 is made of a high thermal conductivity material, it can quickly conduct heat from the target 10 to a wider area. The first cooling device 50 can dissipate heat conducted to the bottom of the target 10. The two work together to improve heat transfer and dissipation efficiency, preventing heat accumulation inside the target structure 100. Furthermore, by providing the first cooling device 50, this embodiment of the application enables the target structure 100 to transition from passive heat dissipation to a combination of passive and active heat dissipation, significantly improving overall heat dissipation efficiency. During the continuous bombardment of the target 10 by the electron beam 202, passive heat dissipation relying solely on the heat dissipation substrate 40 may not be sufficient to handle excessive heat in a timely manner. The first cooling device 50 can quickly and effectively remove heat, allowing the target structure 100 to reduce its temperature within a reasonable range in a short time, ensuring the normal operation of the target structure 100.

[0073] Please see Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of a target structure provided in an embodiment of this application. Figure 3 This is a cross-sectional view of a first cooling device provided in an embodiment of this application. In some embodiments of this application, the first cooling device 50 includes a first flow channel 51, a second flow channel 52, and a third flow channel 53 connected in sequence. The cross-sectional area of ​​the second flow channel 52 is smaller than the cross-sectional areas of the first flow channel 51 and the third flow channel 53. All three flow channels are suitable for flowing with a cooling medium. For example, the cooling medium can be water, an aqueous solution of ethylene glycol, or an aqueous solution of propylene glycol. The orthographic projection of the second flow channel 52 onto a first plane at least partially coincides with the orthographic projection of the target 10 onto a first plane, which is a plane perpendicular to the arrangement direction of the target 10 and the sealing member 30. The second flow channel 52 is capable of heat exchange with the target 10.

[0074] Because the cross-sectional area of ​​the second flow channel 52 is smaller than that of the first flow channel 51 and the third flow channel 53, and the orthographic projection of the second flow channel 52 onto the plane perpendicular to the arrangement direction of the target 10 and the sealing element 30 at least partially coincides with that of the target 10, the second flow channel 52 can directly exchange heat with the target 10. The smaller cross-sectional area allows the cooling medium to flow faster through the second flow channel 52. According to fluid mechanics principles, increased flow velocity enhances the convective heat transfer coefficient, thereby improving the heat exchange efficiency between the cooling medium and the target 10. The overlapping design of the projection of the second flow channel 52 with the target 10 enables precise cooling of key parts of the target 10. During the operation of the target 10, the heating conditions in different areas may vary. The second flow channel 52 can specifically cool the main heating areas. Compared with traditional uniform cooling methods, it can more effectively control the temperature distribution of the target 10, avoid local overheating, and ensure the stability of the target 10's performance.

[0075] It should be noted that the bottom surface of target 10 corresponds to the concentrated heat generation area 11 of target 10 in the area directly irradiated by electron beam 202. This area has a high heat concentration, typically located in the central spot Φ2mm region. Therefore, in one possible structural design, the orthographic projection of the second flow channel 52 onto the first plane coincides with the central region of the orthographic projection of target 10 onto the first plane. This ensures that the cooling medium can directly act on the concentrated heat generation area 11 to quickly remove heat from it, shorten the heat transfer path, and achieve efficient and precise cooling.

[0076] Additionally, the first cooling device 50 may also include a pump body and a heat exchange device, both of which may be externally located. The pump body is connected to the first flow channel 51 and is adapted to deliver the cooling medium into the first flow channel 51. The heat exchange device is connected between the pump body and the third flow channel 53, and is adapted to cool the cooling medium that has heated up after heat exchange with the target 10 (e.g., by exchanging heat with external air or with the cooling medium of other flow channels).

[0077] In this way, the pump body can deliver the cooled medium to the first flow channel 51, and the cooling medium can flow in the circulating flow channel, thereby improving the service life of the first cooling device 50 and reducing maintenance costs.

[0078] In some other embodiments of this application, the target structure 100 further includes a second cooling device 60, which is disposed within the heat dissipation substrate 40 and surrounds the target structure 100 for cooling the target structure 100. Thus, when the target structure 100 heats up as a whole due to bombardment by the electron beam 202, the second cooling device 60 can quickly remove heat from the sides and surrounding areas of the target structure 100, preventing heat from diffusing to other areas.

[0079] Furthermore, when the target structure 100 includes both a first cooling device 50 and a second cooling device 60, the first cooling device 50 cools the bottom of the target structure 100, while the second cooling device 60 cools the sides and surrounding areas of the target structure 100. These two devices complement each other, forming a three-dimensional cooling network. In actual operation, when the target 10 is bombarded by the electron beam 202 and generates heat, the first cooling device 50 rapidly reduces the temperature of the bottom of the target structure 100, preventing heat from being conducted to other parts. Simultaneously, the second cooling device 60 cools the sides of the target structure 100, preventing heat from accumulating on the sides and spreading to the top or other directions. This three-dimensional cooling method can more effectively control the overall temperature of the target structure 100, avoid localized overheating, and ensure that the target structure 100 remains within a suitable operating temperature range in all parts.

[0080] Please see Figure 1 and Figure 4 , Figure 4This is a cross-sectional view of a target structure provided in an embodiment of this application. In some embodiments of this application, the second cooling device 60 is one or more of a cooling jacket assembly and a heat pipe assembly. That is, the second cooling device 60 can be a cooling jacket assembly, a heat pipe assembly, or a combination of a cooling jacket assembly and a heat pipe assembly.

[0081] The cooling jacket assembly is a closed sleeve-shaped structure surrounding the target structure 100, with an internal circulation channel. When the cooling jacket assembly serves as the second cooling device 60, it can be tightly fitted within the heat dissipation substrate 40 and arranged around the target structure 100. The cooling jacket assembly contains a flowing circulating cooling medium, i.e., a cooling medium flowing within the circulation channel. This cooling medium can be the same as or different from the cooling medium in the first cooling device 50; this application does not impose any limitations on this.

[0082] Furthermore, the cooling medium flowing within the circulation channel can be either a liquid or a gaseous cooling medium; this application embodiment does not limit the specific type. For example, the cooling medium flowing within the circulation channel is a liquid (i.e., coolant). The coolant circulates within the channel, absorbing heat generated by the target 10 through direct contact with the sides and surrounding areas of the target structure 100 using the principle of heat conduction. The heated coolant flows out of the cooling jacket, is cooled by external cooling equipment, and then flows back in, forming a continuous cooling cycle. For example, if the cooling medium is a gas, the cooling jacket assembly is a gas cooling jacket. This gas cooling jacket can utilize gas flow to remove heat, achieving efficient cooling by controlling the gas flow rate and temperature.

[0083] Furthermore, the heat pipe assembly consists of a shell, a wick, and end caps. The shell can be made of a metallic material, such as copper alloy or aluminum alloy. This shell possesses good thermal conductivity and mechanical strength, can withstand internal pressure, and protects the internal structure. The shell can be fitted into the heat sink 40 via an interference fit, ensuring excellent heat transfer between them. Additionally, the ends of the shell and the heat sink 40 that house the shell can be riveted to prevent the heat pipe from detaching, increasing structural reliability. The wick can be made of wire mesh, porous ceramic, or fiber material, with numerous tiny pores distributed on its surface. The wick utilizes capillary action to circulate the working fluid within the heat pipe. The end caps seal both ends of the shell to prevent working fluid leakage and maintain a vacuum environment inside the heat pipe.

[0084] The heat pipe assembly is filled with a working fluid, which, for example, may include pure water, ammonia, or methanol. When one end of the heat pipe (evaporation section) comes into contact with a heat-generating object (such as target structure 100), it absorbs heat, causing the working fluid to heat up and evaporate into vapor. Since vapor is less dense than liquid, a pressure difference is created within the pipe, driving the vapor to rapidly flow to the other end of the heat pipe (condensation section). In the condensation section, the vapor encounters a cooler environment or heat dissipation device, releases heat, and condenses back into liquid. The condensed liquid, under the capillary action of the wick, flows back to the evaporation section, absorbs heat again, and evaporates, thus creating a highly efficient heat transfer cycle. In this way, through phase change heat transfer, the heat pipe assembly can transfer heat with extremely high efficiency.

[0085] Thus, by using the heat pipe assembly, the instantaneous heat transfer capability is accelerated, efficiently transferring heat from the target structure 100 outwards, reducing heat accumulation, and effectively lowering the heat flux density at the target structure 100. According to the Arrhenius equation, the relationship between the material's failure rate R and temperature T is: (Ea is the activation energy; k is the Boltzmann constant; T is the absolute temperature). When the temperature decreases, the failure rate R will decrease significantly, thereby extending the lifetime of target 10.

[0086] In one possible structural design, the heat pipe assembly includes a plurality of heat pipes 61 arranged circumferentially along the target 10, all of which are thermally connected to the target structure 100. Optionally, the plurality of heat pipes 61 may be evenly spaced circumferentially along the target 10.

[0087] Because multiple heat pipes 61 are arranged circumferentially around the target 10, the heat pipe assembly can have a large contact area with the target structure 100. When the target 10 generates heat under conditions such as bombardment by the electron beam 202, the evaporation sections of the multiple heat pipes 61 can be in close contact with the surface of the target 10, rapidly absorbing heat. Due to the phase change heat transfer principle of the heat pipes 61, the working liquid absorbing heat can be rapidly evaporated into steam, and the steam flows to the condensation section under the action of pressure difference to release heat and condense back, thus achieving efficient heat transfer and dissipation of the target structure 100. The arrangement of multiple heat pipes 61 circumferentially around the target 10 can remove heat from all sides of the target 10 in a timely manner, avoiding heat accumulation in local areas of the target 10 and ensuring uniform temperature distribution of the target structure 100.

[0088] In another possible structural design, the heat pipe assembly includes a heat pipe 61, which is arranged to spirally wrap around the target structure 100 along the axial direction of the target structure 100, and the heat pipe 61 is thermally connected to the target structure 100.

[0089] Thus, when the target structure 100 generates heat under conditions such as bombardment by the electron beam 202, the portion of the heat pipe 61 in contact with the target 10 (evaporation section) absorbs the heat, causing the internal working liquid to evaporate into vapor. Driven by the pressure difference within the pipe, the vapor flows along a spiral path to a lower temperature region (condensation section), where it releases heat and condenses back into liquid. Subsequently, under the capillary action of the wick, the liquid flows back along the spiral path to the evaporation section, thus repeating the cycle to achieve continuous and efficient heat transfer and dissipation from the target structure 100. This embodiment employs a spiral-wound arrangement of a single heat pipe 61, allowing it to contact multiple parts of the target structure 100, absorbing heat from all directions and ensuring effective heat dissipation. Furthermore, the required number of heat pipes 61 is small, which helps reduce the manufacturing cost of the target structure 100.

[0090] In some embodiments of this application, a heat dissipation substrate 40 is provided on its outer surface with a heat radiation film 70, which is used to facilitate heat exchange between the heat dissipation substrate 40 and the outside. The heat radiation film 70 may be a black radiation film.

[0091] Optionally, the material of the thermal radiation film 70 can be a metal oxide, such as aluminum oxide (Al2O3), titanium dioxide (TiO2), zinc oxide (ZnO), etc. Alternatively, the material of the thermal radiation film 70 can also be a ceramic material, a high-molecular polymer composite material, etc., and this application does not limit this choice.

[0092] It should be noted that thermal radiation is the process by which an object transfers heat outward in the form of electromagnetic waves, and it can occur without a medium. The thermal radiation film 70 is typically made of a material with high emissivity, which can efficiently absorb heat from the surface of the heat dissipation substrate 40 and radiate it into the surrounding environment in the form of thermal radiation. Thus, when the heat dissipation substrate 40 absorbs heat transferred from the target structure 100 and other heat dissipation components, its temperature rises. The thermal radiation film 70 quickly absorbs this heat and converts it into electromagnetic waves that are radiated into the external environment, thereby achieving heat exchange between the heat dissipation substrate 40 and the outside world, reducing the temperature of the heat dissipation substrate 40 itself, and indirectly assisting the heat dissipation of the target structure 100.

[0093] In addition, the second cooling device 60, the first cooling device 50 and the thermal radiation film 70 achieve combined heat dissipation through heat conduction, heat convection and heat radiation, thereby enhancing the heat dissipation capacity of the target structure 100.

[0094] In some embodiments of this application, the heat dissipation substrate 40 includes heat dissipation fan fins 80, which are thermally connected to the heat dissipation substrate 40. The heat dissipation fan fins 80 are disposed on the outer surface of the heat dissipation substrate 40, thereby increasing the contact area between the heat dissipation substrate 40 and the external air.

[0095] Thus, the heat dissipation fan fins 80 increase the contact area between the heat dissipation substrate 40 and the external air, thereby increasing the effective heat dissipation area of ​​the heat dissipation substrate 40 and improving its heat exchange efficiency. Compared to a heat dissipation substrate 40 without heat dissipation fan fins 80, the heat dissipation substrate 40 with heat dissipation fan fins 80 can dissipate more heat in the same amount of time, allowing the heat generated by the target structure 100 to be transferred to the external environment more quickly.

[0096] Secondly, this application also provides an accelerator tube assembly 1000, which includes a target structure 100 and an accelerator tube body 200. The accelerator tube body 200 has an electron beam outlet 201. The sealing end of the sealing member 30 of the target structure 100 is disposed at the electron beam outlet 201 of the accelerator tube body 200 to seal the accelerator tube body and maintain a vacuum state inside the accelerator tube. The target structure 100 is described in the first aspect above, and will not be repeated here.

[0097] It should be noted that the accelerator tube 200 is the core of electron acceleration. Through the electric or electromagnetic field set inside, electrons are accelerated to obtain higher energy and are finally emitted from the electron beam outlet 201.

[0098] In the accelerator tube assembly 1000 provided in this application embodiment, the accelerator tube body 200 is sealed using a target structure 100. First, the vacuum chamber of the accelerator tube body 200 and the target 10 are isolated by the sealing element 30 of the target structure 100. Even if the target 10 develops cracks / microcracks due to electron beam bombardment, the vacuum state of the vacuum chamber inside the accelerator tube body 200 will not be affected. Second, since the anti-oxidation layer 20 of the target structure 100 has high ductility, when the electron beam 202 bombards the target 10, the target 10 may develop microcracks, but the anti-oxidation layer 20, due to its high ductility, will not develop microcracks. Even if the end of the sealing element 30 facing the electron beam outlet 201 is damaged / cracked at the position bombarded by the electron beam 202, the anti-oxidation layer 20 can still maintain the vacuum state of the accelerator tube body 200, thereby extending the service life of the accelerator tube assembly 1000.

[0099] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions 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 target structure, characterized in that, include: Target, antioxidant layer and seals; The sealing element is a hollow cylindrical structure that is closed at one end and open at the other end. It is disposed above the target, with the open end of the sealing element located close to the target for sealing the target. The antioxidant layer is disposed on the surface of the target on the side bombarded by the electron beam; the antioxidant layer has higher antioxidant properties and ductility than the target material.

2. The target structure according to claim 1, characterized in that, The hollow portion of the seal and the cavity formed by the target are in a vacuum state.

3. The target structure according to claim 1 or 2, characterized in that, The target structure further includes a gradient heat dissipation component, which is disposed around the target structure. The gradient heat dissipation component includes multiple layers of gradient heat dissipation material with progressively increasing thermal conductivity from the direction close to the target structure to the direction away from the target structure.

4. The target structure according to claim 1 or 2, characterized in that, The target structure also includes a heat dissipation substrate, and the target and the sealing element are embedded in the heat dissipation substrate.

5. The target structure according to claim 4, characterized in that, The target structure further includes a first cooling device, which is disposed in the substrate and located at the bottom of the target, for cooling the target structure.

6. The target structure according to claim 5, characterized in that, The first cooling device includes a first flow channel, a second flow channel, and a third flow channel connected in sequence. The cross-sectional area of ​​the second flow channel is smaller than the cross-sectional areas of the first flow channel and the third flow channel. The orthographic projection of the second flow channel on a first plane at least partially coincides with the orthographic projection of the target on the first plane. The first plane is a plane perpendicular to the arrangement direction of the target and the seal. The second flow channel is capable of heat exchange with the target.

7. The target structure according to claim 4, characterized in that, The target structure further includes a second cooling device, which is disposed within the heat dissipation substrate and surrounds the target structure for cooling the target structure.

8. The target structure according to claim 7, characterized in that, The second cooling device is one or more of a cooling jacket assembly and a heat pipe assembly.

9. The target structure according to claim 8, characterized in that, When the second cooling device is a cooling jacket assembly, there is a flowing circulating cooling medium inside the cooling jacket assembly; When the second cooling device is a heat pipe assembly The heat pipe assembly includes multiple heat pipes arranged circumferentially along the target, and all heat pipes are thermally connected to the target structure; or The heat pipe assembly includes a heat pipe that is spirally wrapped around the target structure along the axial direction of the target structure, and the heat pipe is thermally connected to the target structure.

10. The target structure according to claim 4, characterized in that, The outer surface of the heat dissipation substrate is provided with a heat radiation film, which is used to enable the heat dissipation substrate to exchange heat with the outside.

11. The target structure according to claim 4, characterized in that, The heat dissipation substrate includes heat dissipation fan fins, which are thermally connected to the heat dissipation substrate.

12. An accelerator tube assembly, characterized in that, include: An accelerating tube body having an electron beam outlet and a target structure according to any one of claims 1-11, wherein the sealing end of the sealing member of the target structure is located at the electron beam outlet of the accelerating tube body for sealing the accelerating tube body and maintaining it in a vacuum state.

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