A magnetic alloy high frequency system

Abstract

The application belongs to the technical field of particle accelerators, and discloses a magnetic alloy high-frequency system, which comprises a magnetic alloy loading cavity and a power source. The magnetic alloy loading cavity comprises a cavity shell, an inner conductor assembly, a wall-penetrating assembly and a feed electrode. The inner conductor assembly is coaxially arranged in the inside of the cavity shell. The wall-penetrating assembly is sealingly connected to the periphery of the cavity shell. The feed electrode is electrically connected to the inner conductor assembly after penetrating the wall-penetrating assembly. The number of the wall-penetrating assembly and the feed electrode is both two and they are one-to-one corresponding. The two feed electrodes are arranged at an interval of 90 degrees along the circumference of the cavity shell. The power source is connected to the cavity shell through a power transmission pipeline. A high-frequency transmission body is arranged in the power transmission pipeline. One end of the high-frequency transmission body is connected to the feed electrode, and the other end of the high-frequency transmission body is connected to the power source. The magnetic alloy high-frequency system provided by the application significantly increases the physical creepage distance between the two high-voltage feed electrodes, and effectively reduces the probability of spark between the poles in the compact space.

Description

Technical Field

[0001] This invention relates to the field of particle accelerator technology, and more particularly to a magnetic alloy high-frequency system. Background Technology

[0002] Magnetic alloy high-frequency systems have important applications in particle accelerators. They typically operate in the frequency band above MHz and withstand peak voltages on the order of kV. They also have broad prospects in materials science, nuclear medicine, radiobiology, and the diagnosis and treatment of diseases.

[0003] In existing technologies, to achieve high gradients, systems typically employ a push-pull feeding mode. This involves two power sources feeding power to opposite ends of a ceramic gap, with a 180-degree phase difference between the voltages at both ends. This causes particles to experience twice the high-frequency voltage as they pass through the ceramic gap. However, the feeding electrodes of the two power sources are usually positioned on the same straight line (e.g., both at 0 or 180 degrees). Within the compact cavity space, the two output electrodes are too close together, making arcing between them highly likely. This defect in the feeding structure has become one of the main bottlenecks limiting further increases in the system's acceleration gradient.

[0004] Therefore, there is an urgent need to provide a high-frequency magnetic alloy system to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a magnetic alloy high-frequency system that significantly increases the physical creepage distance between two high-voltage feed electrodes, effectively reducing the probability of inter-electrode arcing in a compact space.

[0006] To achieve this objective, the present invention adopts the following technical solution: A magnetic alloy high-frequency system, comprising: A magnetic alloy loading cavity includes a cavity shell, an inner conductor assembly, a through-wall assembly, and a feeding electrode. The inner conductor assembly is coaxially disposed inside the cavity shell. The through-wall assembly is sealed and connected to the periphery of the cavity shell. The feeding electrode passes through the through-wall assembly and is electrically connected to the inner conductor assembly. The feeding electrode is insulated from the through-wall assembly. The number of the through-wall assembly and the feeding electrode are both set to two and they are matched one-to-one. The two feeding electrodes are arranged at a 90° interval along the circumference of the cavity shell. A power source is connected to the outer shell of the cavity via a power transmission pipe. The power transmission pipe is covered outside the through-wall assembly. A high-frequency transmitter, corresponding to the feed electrode, is installed inside the power transmission pipe. One end of the high-frequency transmitter is connected to the feed electrode, and the other end of the high-frequency transmitter is connected to the power source.

[0007] As an alternative, the interior of the inner conductor assembly is a vacuum cavity, and two first cavities and a second cavity connecting the two first cavities are formed between the inner conductor assembly and the cavity shell. Both the first and second cavities are filled with insulating gas, the through-wall assembly can seal the second cavity, and the feed electrode is located in the second cavity.

[0008] As an optional solution, the inner conductor assembly includes a beam channel, a ceramic tube, and conductive copper rings. The conductive copper rings are connected to both ends of the ceramic tube. The beam channel is connected to both ends of the ceramic tube through the conductive copper rings. The two feed electrodes are electrically connected to different conductive copper rings.

[0009] As an alternative, the bottom of the opposite sides of the second cavity is provided with inner conductor walls, and the two inner conductor walls are provided in a one-to-one correspondence with the two conductive copper rings. Each inner conductor wall is connected to the corresponding conductive copper ring by a feeding copper busbar, and the two feeding electrodes are respectively connected to different inner conductor walls.

[0010] As an optional solution, the power supply copper bus includes a toothed annular body and multiple copper bus bodies. The toothed annular body is fixedly mounted on the conductive copper ring. The multiple copper bus bodies are arranged at intervals along the circumference of the toothed annular body, and one end of each copper bus body is connected to one of the teeth of the toothed annular body. The other end of each copper bus body is connected to the inner conductor wall.

[0011] As an optional solution, a voltage sampling module is also included, which includes an L-shaped connecting copper busbar, a ceramic vacuum capacitor, and a metal shielding cap. One end of the L-shaped connecting copper busbar is connected to the high-voltage end of the high-frequency transmission body, and the other end of the L-shaped connecting copper busbar is connected to the high-voltage end of the ceramic vacuum capacitor. The metal shielding cap is installed on the low-voltage end of the ceramic vacuum capacitor and connected to the outer wall of the power transmission pipeline. Several high-frequency ceramic capacitors connected in parallel are integrated and installed in the internal space of the metal shielding cap.

[0012] As an optional solution, the through-wall assembly includes a first ceramic plate and a second ceramic plate arranged coaxially. The feeding electrode passes through the first ceramic plate and the second ceramic plate in sequence, forming a sealed cavity between the first ceramic plate and the second ceramic plate. The sealed cavity is filled with a cooling medium. A medium inlet is provided on one side of the sealed cavity, and a medium outlet is provided on the other side of the sealed cavity.

[0013] As an alternative, the outer peripheries of the first ceramic sheet and the second ceramic sheet are brazed to a metal flange through a metallization layer, and the metallization layer together with the first ceramic sheet and the second ceramic sheet forms the sealed cavity.

[0014] As an alternative, at least one of the first ceramic sheet and the second ceramic sheet has grooves formed on its surface to increase the creepage distance.

[0015] As an optional solution, the first ceramic sheet and the second ceramic sheet are high-purity, high-density alumina ceramics with a purity ≥99.5% and a density ≥3.90 g / cm3; Alternatively, the first ceramic sheet and the second ceramic sheet may be aluminum nitride ceramic or beryllium oxide ceramic.

[0016] The beneficial effects of this invention are: This invention provides a magnetic alloy high-frequency system, including a magnetic alloy loading cavity and a power source. The magnetic alloy loading cavity includes a cavity shell, an inner conductor assembly, a through-wall assembly, and a feed electrode. The inner conductor assembly is coaxially disposed inside the cavity shell. The through-wall assembly is sealed and connected to the periphery of the cavity shell. The feed electrode is electrically connected to the inner conductor assembly after being insulated through the through-wall assembly. Two through-wall assemblies and two feed electrodes are provided, each corresponding to the other. The two feed electrodes are spaced 90° apart circumferentially around the cavity shell. For push-pull operation, the two feed electrodes are spatially offset by 90°, significantly increasing the physical creepage distance (insulation distance) between the two high-voltage feed electrodes in a compact space, effectively reducing the probability of inter-electrode arcing in a compact space. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the magnetic alloy high-frequency system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the magnetic alloy high-frequency system after the sidewall of the power transmission pipe portion is hidden, as provided in an embodiment of the present invention. Figure 3 This is an isometric sectional view of the magnetic alloy loading cavity provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the wall-penetrating component provided in an embodiment of the present invention; Figure 5 yes Figure 3 A magnified view of a section at point B in the middle; Figure 6 This is a schematic diagram of the power supply copper busbar provided in an embodiment of the present invention; Figure 7 yes Figure 2 A magnified view of a section at point A in the middle; Figure 8This is a schematic diagram of the voltage acquisition module provided in an embodiment of the present invention.

[0018] In the picture: 10. Magnetic alloy loading cavity; 11. Cavity shell; 111. First cavity; 112. Second cavity; 113. Third cavity; 114. Inner conductor wall; 12. Inner conductor assembly; 121. Beam channel; 122. Ceramic tube; 123. Conductive copper ring; 124. Vacuum cavity; 13. Blind flange; 14. Through-wall assembly; 141. First ceramic plate; 142. Second ceramic plate; 143. Sealed cavity; 144. Medium inlet; 145. Medium outlet; 146. Metallization layer; 147. Metal flange; 148. Groove; 15. Feed electrode; 16. Magnetic alloy ring; 17. Feed copper busbar; 171. Toothed annular body; 172. Copper busbar body; 20. Power source; 30. Power transmission pipeline; 40. High-frequency transmission body; 50. Voltage sampling module; 51. L-shaped connecting copper busbar; 52. Ceramic vacuum capacitor; 53. Metal shielding cap; 60. Support platform. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0020] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] This embodiment provides a magnetic alloy high-frequency system for use in particle accelerators. For example... Figure 1 As shown, the magnetic alloy high-frequency system mainly includes a magnetic alloy loading cavity 10 and a power source 20. The power source 20 is used to feed power into the magnetic alloy loading cavity 10, thereby establishing an electromagnetic field in the magnetic alloy loading cavity 10. Optionally, the magnetic alloy high-frequency system also includes a support platform 60, which is located at the bottom of the magnetic alloy loading cavity 10 and is used to support the magnetic alloy loading cavity 10. In some optional embodiments, the support platform 60 can be configured to be height-adjustable to adjust the height position of the magnetic alloy loading cavity 10. The specific structure of the support platform 60 is prior art and will not be described in detail here.

[0024] Specifically, such as Figure 2 and Figure 3 As shown, the magnetic alloy loading cavity 10 includes a cavity shell 11, an inner conductor assembly 12 coaxially disposed inside the cavity shell 11, and blind flanges 13 connecting the cavity shell 11 and the inner conductor assembly 12 at both axial ends. The inner conductor assembly 12 has a tubular structure, and the interior of the inner conductor assembly 12 is a vacuum cavity 124. The vacuum cavity 124 is used to provide a motion environment for particles and accelerate particles according to the accelerating voltage. Two annular third cavities 113 are formed inside the cavity shell 11, spaced apart along the axial direction. Each third cavity 113 contains multiple (e.g., 3) magnetic alloy rings 16, and the inner conductor assembly 12 coaxially passes through multiple magnetic alloy rings 16. Each third cavity 113 can be regarded as an independent water-cooled sealed metal box, and the magnetic alloy rings 16 can be directly immersed in cooling water for heat dissipation.

[0025] The magnetic alloy-loaded cavity is a type of large-scale high-power radio frequency device. It is a coaxial resonant cavity that uses magnetic alloy material as the inductor loading material. Due to the characteristics of high permeability, high saturation magnetic flux density, high Curie temperature and low Q value of magnetic alloy material, it can achieve wide bandwidth (1-10MHz) and high gradient operation. Compared with high-frequency cavities loaded by traditional inductor materials, the cavity length can be shorter, the acceleration gradient of the cavity can be higher, and the operating frequency band of the cavity is wider. The cavity does not require tuning, that is, there is no need to wind a bias winding on the magnetic alloy ring 16 and apply a DC magnetic field to change its permeability. This eliminates the need for a complex tuning control system, which greatly simplifies the complex tuning control loop and makes the cavity operation more stable. Therefore, it is often used in the field of high-power particle accelerators to meet the physical requirements of high beam current, short pulse width and high stability.

[0026] like Figure 3 and Figure 5As shown, the inner conductor assembly 12 includes a beam channel 121, a ceramic tube 122, and a conductive copper ring 123. Both ends of the ceramic tube 122 are connected to the conductive copper ring 123. The beam channel 121 is connected to both ends of the ceramic tube 122 via the conductive copper ring 123. The section of the ceramic tube 122 in the middle of the beam channel 121 serves as the ceramic gap, used to isolate the vacuum and allow a high-frequency electric field to penetrate and accelerate particles. This is the area with the highest voltage and the easiest point for sparking. The beam channel 121 can be made of stainless steel.

[0027] Furthermore, such as Figure 3 As shown, the magnetic alloy loading cavity 10 also includes a through-wall assembly 14 and a feed electrode 15. The through-wall assembly 14 is sealed to the periphery of the cavity shell 11. The feed electrode 15 passes through the through-wall assembly 14 and is electrically connected to the conductive copper ring 123 of the inner conductor assembly 12. The feed electrode 15 and the through-wall assembly 14 are insulated from each other. The power source 20 is connected to the cavity shell 11 through a power transmission pipe 30. The power transmission pipe 30 is covered outside the through-wall assembly 14. A high-frequency transmission element 40 corresponding to the feed electrode 15 is provided inside the power transmission pipe 30. One end of the high-frequency transmission element 40 is connected to the feed electrode 15, and the other end of the high-frequency transmission element 40 is connected to the power source 20. The feed electrode 15 can be a copper busbar. The power source 20 is electrically connected to the conductive copper ring 123 through the high-frequency transmission element 40 and the feed electrode 15 in sequence, thereby forming a power transmission line to feed power into the ceramic gap.

[0028] In this embodiment, as Figure 2 As shown, the number of through-wall components 14 and feed electrodes 15 are both set to two and are matched one-to-one. The two feed electrodes 15 are electrically connected to different conductive copper rings 123. The two feed electrodes 15 represent positive and negative output electrodes, and are respectively connected to different conductive copper rings 123 at both ends of the ceramic tube 122, so that the ceramic gap is an acceleration gap. When a particle beam is injected into one of the beam channels 121, the charged particles are accelerated through the ceramic gap and then extracted from the other beam channel 121.

[0029] In existing technologies, to achieve a high gradient, the system employs a push-pull operating mode, where two power sources 20 feed power to both ends of the ceramic gap, with opposite voltage polarities and a 180-degree phase difference, causing particles to experience twice the high-frequency voltage as they pass through the ceramic gap. However, the feed electrodes 15 of the two power sources 20 are typically positioned on the same straight line (e.g., both at 0 or 180 degrees). Within the compact cavity space, the two feed electrodes 15 are too close together, making them highly susceptible to arcing. This defect in the feed structure has become one of the main bottlenecks limiting further improvement in the system's acceleration gradient.

[0030] To solve the above problems, such as Figure 2As shown, in this embodiment, the two feed electrodes 15 are arranged at a 90° interval along the circumference of the cavity shell 11. For the push-pull working mode, the two feed electrodes 15 are spatially offset by 90°, which significantly increases the physical creepage distance (insulation distance) between the two high-voltage feed electrodes 15 in the compact space, effectively reducing the probability of inter-electrode arcing in the compact space.

[0031] In the prior art, the outer area of ​​the conventional beam pipe 121 is exposed to the atmospheric environment, which is highly susceptible to humidity and dust, resulting in a reduction in the ignition threshold.

[0032] To solve the above problems, such as Figure 3 As shown, in this embodiment, two first cavities 111 are formed between the inner conductor assembly 12 and the cavity shell 11, and a second cavity 112 is connected between the two first cavities 111. The through-wall assembly 14 can seal the second cavity 112. The feed electrode 15 is located inside the second cavity 112, and the ceramic tube 122 and the conductive copper ring 123 are both facing the inside of the second cavity 112. The first cavity 111 is located radially inside the third cavity 113, and the second cavity 112 is located between the two third cavities 113. The blind flanges 13 at both ends are sealed to the cavity shell 11 and the inner conductor assembly 12, so that the vacuum cavity 124 inside the inner conductor assembly 12 and the first cavity 111 and the second cavity 112 outside the inner conductor assembly 12 are both sealed spaces. The first cavity 111 and the second cavity 112 are both filled with insulating gas, which can be SF6 gas, as SF6 gas has better insulation properties.

[0033] During operation, the vacuum chamber 124 inside the inner conductor assembly 12 is in an ultra-high vacuum state, with a vacuum level reaching 1E-6 Pa. The first cavity 111 and the second cavity 112 outside the inner conductor assembly 12 are filled with SF6 gas. Through the feeding electrode 15, the power source 20 is fed to both ends of the ceramic tube 122. By maintaining the ultra-high vacuum in the vacuum chamber 124 inside the inner conductor assembly 12 and filling the first cavity 111 and the second cavity 112 outside the inner conductor assembly 12 with SF6 insulating gas, a double composite insulation method is formed. Under extremely high gradient conditions, it can maintain the overall compact structure, block the flashover path in the high-voltage area, avoid the risk of gap breakdown, effectively suppress arcing, and significantly improve the withstand voltage and operational reliability of the magnetic alloy loading cavity 10, realizing the compact high gradient design of the magnetic alloy loading cavity 10.

[0034] It should be noted that in this embodiment, the through-wall component 14, as a key interface component, undertakes two core functions: first, to achieve reliable sealing and isolation between the second cavity 112 and the external atmospheric environment; and second, to maintain long-term insulation reliability of the feed electrode 15 at the cavity wall under high-frequency and high-voltage operating conditions.

[0035] In existing technologies, common wall-penetrating components 14 are mostly designed based on power frequency (50Hz / 60Hz) conditions, and their material selection, structural form, and withstand voltage assessment are mainly suitable for low-frequency, high-voltage applications. However, when the operating frequency is increased to above MHz, the ceramic material of the traditional wall-penetrating component 14 will generate significant dielectric losses under high-frequency alternating electric fields, causing local temperature rise, resulting in a decrease in the material's insulation performance, a significant reduction in withstand voltage, and a tendency to thermal breakdown. This makes it difficult to meet the stringent requirements of accelerator high-frequency loading cavities for insulation reliability, long-term stability, and power tolerance.

[0036] Therefore, such as Figure 4 As shown, in this embodiment, the through-wall assembly 14 includes a first ceramic plate 141 and a second ceramic plate 142 coaxially arranged. The feed electrode 15 passes through the first ceramic plate 141 and the second ceramic plate 142 in sequence, forming a sealed cavity 143 between the first ceramic plate 141 and the second ceramic plate 142. The sealed cavity 143 is filled with a cooling medium. A medium inlet 144 is provided on one side of the sealed cavity 143, and a medium outlet 145 is provided on the other side of the sealed cavity 143. Specifically, the outer peripheries of the first ceramic plate 141 and the second ceramic plate 142 are brazed and sealed to a metal flange 147 through a metallization layer 146. The metal flange 147 can be selected as two flanges arranged vertically and vertically. The lower metal flange 147 can be connected to the outer shell 11 of the cavity. The medium inlet 144 and the medium outlet 145 are respectively provided on the metallization layer 146. The metallization layer 146, the first ceramic plate 141, and the second ceramic plate 142 together enclose the aforementioned sealed cavity 143.

[0037] Both the medium inlet 144 and the medium outlet 145 are connected to the cooling system, forming a closed-loop or unidirectional cooling channel. During operation, the cooling medium is forcibly pumped into the sealed cavity 143 through the medium inlet 144. As it flows through the inner surfaces of the first ceramic plate 141 and the second ceramic plate 142, it directly and efficiently removes the heat generated by the high-frequency medium loss of the ceramic plates, directly and specifically solving the problem of high-frequency loss heat generation, ensuring that the temperature rise of the through-wall assembly 14 is controllable when operating at full power. In the prior art, single-layer solid ceramic plates are mostly used, and heat dissipation relies solely on natural convection or conduction on the surface of the ceramic plates, which is inefficient and uneven. However, this application uses coaxially arranged double-layer ceramic plates, which are sealed with an outer periphery to form an annular sealed cavity 143. An external forced cooling system is connected to the sealed cavity 143 for convective heat dissipation, realizing the direct, efficient, and uniform removal of heat loss inside the through-wall assembly 14. This solves the problem of thermal stress cracking caused by uneven heat dissipation at high frequencies and achieves active control of the operating temperature.

[0038] Specifically, by adopting the aforementioned through-wall assembly 14, three major effects can be achieved: First, uniform heat dissipation. Since the cooling medium in the sealed cavity 143 has a large contact area with both ceramic plates (heating elements), heat is dissipated synchronously and uniformly, fundamentally avoiding the huge radial temperature difference and thermal stress caused by uneven heat dissipation on the inner and outer surfaces of traditional solid or single-layer ceramic plates. Second, thermal stress elimination. The uniform temperature field makes the thermal expansion of the ceramic plates uniform and consistent, effectively preventing ceramic cracking or brazing seal failure caused by thermal stress concentration, greatly improving the mechanical reliability and lifespan of the through-wall assembly 14. Finally, active temperature control capability. By adjusting the flow rate and velocity of the cooling system, the operating temperature of the through-wall assembly 14 can be actively controlled to ensure that it always operates within the optimal temperature range and has stable performance.

[0039] In one optional embodiment, the cooling system may be a forced air cooling system, and the cooling medium is not limited to dry air. It may also be nitrogen (N2), sulfur hexafluoride (SF6) or other fluorinated inert gases with better insulation properties to further enhance the insulation of the sealed cavity 143 itself. No specific limitation is made here.

[0040] In another alternative embodiment, the cooling system may also be a forced liquid cooling system, and the cooling medium may be an insulating coolant, such as a fluorinated liquid. The forced liquid cooling system may include a micro-circulation pump and a radiator, which has higher heat dissipation efficiency, but the system is more complex.

[0041] In another alternative embodiment, the sealed cavity 143 may not be completely sealed. It may be designed to allow a small amount of cooling gas to seep in or out, forming a slight positive pressure, which can both dissipate heat and prevent external contaminants from entering.

[0042] In this embodiment, the ceramic sheet is configured as two layers (first ceramic sheet 141 and second ceramic sheet 142). In other optional embodiments, the ceramic sheet can also be configured as two or more layers to form two or more series-connected sealed cooling cavities, which are suitable for through-wall components 14 with higher voltage levels and longer lengths, and realize graded management of voltage gradient and heat.

[0043] In the prior art, the wall-penetrating component 14 designed based on power frequency conditions has no special requirements for the purity, density and high-frequency loss characteristics of ceramics, and often uses low-cost, general-performance industrial ceramics.

[0044] In this embodiment, the first ceramic sheet 141 and the second ceramic sheet 142 can be made of materials with a purity ≥99.5% and a density ≥3.90 g / cm³. 3The high purity and high density of alumina ceramics ensure that there are very few impurity ions at the grain boundaries, thereby directly reducing ion polarization loss and conductivity loss under high frequency electric fields. The high density significantly reduces the micropores inside the ceramic sheet, eliminates the hidden danger of internal partial discharge, and directly improves the breakdown voltage threshold of the ceramic sheet, laying the foundation for high voltage and high frequency operation.

[0045] In other alternative embodiments, besides the high-purity alumina ceramic described above, the first ceramic sheet 141 and the second ceramic sheet 142 can also be made of aluminum nitride ceramic or beryllium oxide ceramic. Aluminum nitride ceramic is also an option due to its higher thermal conductivity, making it particularly suitable for applications with extremely high thermal management requirements. While beryllium oxide ceramic has extremely high thermal conductivity, its toxicity necessitates special treatment. Other options, such as lead zirconate titanate-based composite ceramics, can also achieve low losses at specific frequencies through formulation adjustments.

[0046] In summary, in this embodiment, by selecting high-purity, high-density alumina ceramic as the insulating body, its dielectric loss at high frequencies is reduced, and the breakdown voltage of the ceramic sheet is increased. By adopting a double-ceramic-sheet composite structure, a sealed cavity 143 is formed between the two ceramic sheets, and a cooling system is introduced to force convection heat dissipation of the sealed cavity 143, ensuring uniform temperature distribution of the ceramic sheets and avoiding thermal stress cracking due to local overheating. This significantly reduces the dielectric loss and temperature rise of the through-wall assembly 14 under high-frequency operating conditions. Therefore, through the coordinated optimization of the ceramic material selection and structural design of the through-wall assembly 14, low loss, high withstand voltage, uniform heat dissipation, and reliable sealing of the through-wall assembly 14 under high voltage and high frequency conditions are achieved. It is especially suitable for special occasions in particle accelerators where the magnetic alloy loading cavity 10 requires high frequency, high voltage, and high reliability.

[0047] In existing technologies, the surfaces of ceramic sheets are mostly smooth planes or simple skirts, without sophisticated design to address the concentration of surface electric fields under high frequency and high voltage. In this embodiment, however, at least one of the first ceramic sheet 141 and the second ceramic sheet 142 may have grooves 148 formed on its surface to increase the creepage distance. By designing grooves 148 of a specific form on the surface of the ceramic sheet, the actual creepage distance on the ceramic sheet surface is increased. When there is a risk of surface discharge, the discharge development path is repeatedly "torsionalized" and "stretched" by the grooves 148, extending the surface flashover path and significantly improving the surface flashover voltage of the ceramic sheet. This feature specifically addresses the surface discharge problem caused by the concentration of edge electric fields in conductors under high voltage and high frequency, and is key to improving the insulation capability of the through-wall assembly 14.

[0048] In addition, it should be noted that by combining high-purity dense ceramic material and the groove 148 on the surface of the ceramic sheet, the breakdown voltage and surface flashover voltage of the through-wall component 14 are significantly improved, which multiplies its insulation safety margin under MHz high frequency and tens of kilovolt high voltage, fundamentally reducing the risk of thermal breakdown and electrical breakdown, and enhancing the insulation stability and reliability of the through-wall component 14 under harsh electric field conditions.

[0049] In this embodiment, grooves 148 are formed on both sides of the first ceramic sheet 141 and the second ceramic sheet 142. Optionally, the grooves 148 can be concentric annular grooves, spiral grooves, or a series of radially distributed array grooves. The grooves 148 are not limited to mechanical engraving; they can also be made by laser ablation, abrasion, or molding. The shape of the grooves 148 can be optimized using electric field simulation software to form a personalized array of grooves with non-uniformity, gradual depth, or curvature, in order to achieve optimal field strength homogenization.

[0050] Optionally, the groove 148 may be filled with a dielectric material with high resistivity and high thermal conductivity. Specifically, the groove 148 may be filled or coated with silicone grease or epoxy composite material with high resistivity and high thermal conductivity to further improve electric field uniformity and heat dissipation.

[0051] Optionally, the through-wall assembly 14 also includes a sensor for monitoring the temperature or pressure within the sealed cavity 143. The sensor enables active control of the operating temperature or pressure within the sealed cavity 143, ensuring it always operates within the optimal temperature or pressure range and maintains stable performance.

[0052] Optionally, elastic sealing rings are provided between the feed electrode 15 and the first ceramic plate 141, and between the feed electrode 15 and the second ceramic plate 142. The elastic sealing rings can provide auxiliary sealing and stress buffering. Optionally, the elastic sealing rings can be made of fluororubber O-rings resistant to high and low temperatures.

[0053] Alternatively, in addition to the aforementioned elastic sealing ring, a fully rigid seal can be achieved by glass sealing or secondary brazing on the entire outer side of the through-wall assembly 14, which is suitable for environments with extremely strict requirements for gas purity or vacuum environments.

[0054] Optionally, an equalizing ring is added to the end of the feed electrode 15 to further improve the electric field distribution and suppress corona discharge.

[0055] In summary, the above-described through-wall component 14 is suitable for high-frequency environments above MHz and high-voltage environments of tens of kilovolts, and has low loss, high pressure resistance, excellent heat dissipation characteristics and reliable sealing performance, breaking through the technical bottleneck of the performance and reliability of the magnetic alloy loading cavity 10 and even the entire accelerator system.

[0056] In the existing technology, the heavy power supply copper busbar is usually directly connected to the conductive copper rings 123 on both sides of the ceramic tube 122 by bolts. This results in high mechanical stress, high installation difficulty, easy breakage and damage to the ceramic during installation, and poor contact can lead to local overheating.

[0057] To solve the above problems, combined with Figure 3 and Figure 5 In this embodiment, inner conductor walls 114 are respectively provided at the bottom of opposite sides of the second cavity 112. The two inner conductor walls 114 are respectively provided with two conductive copper rings 123. Each inner conductor wall 114 and the corresponding conductive copper ring 123 are connected by a feed copper busbar 17. The two feed electrodes 15 are respectively connected to different inner conductor walls 114. The feed electrodes 15 are electrically connected to the conductive copper rings 123 through the inner conductor walls 114, the feed copper busbar 17, and the conductive copper rings 123 in sequence. The resistivity of the feed copper busbar 17 is extremely low, and its core function is to establish a low-loss, high-reliability high-frequency high-current path.

[0058] Specifically, such as Figure 5 and Figure 6 As shown, the power supply copper bus 17 includes a toothed annular body 171 and multiple copper bus bodies 172. The toothed annular body 171 is fixedly fitted on the conductive copper ring 123 and has multiple protruding teeth along the circumferential direction. The multiple copper bus bodies 172 are arranged at intervals along the circumference of the toothed annular body 171, and one end of each copper bus body 172 is integrally formed and connected to the multiple teeth of the toothed annular body 171. The other end of each copper bus body 172 is connected to the inner conductor wall 114.

[0059] By fixing one end of the copper busbar body 172 to the robust inner conductor wall 114 with bolts, the weight and mechanical torque are borne by the metal inner conductor wall 114. The toothed annular body 171 is fixedly fitted to the outside of the conductive copper ring 123 with bolts. The toothed annular body 171 is elastic and can absorb installation tolerances and thermal expansion, reducing mechanical stress. In addition, the toothed annular body 171 fits closely with the conductive copper ring 123, with a large contact area, ensuring effective contact of high-frequency current.

[0060] It should be noted that the toothed annular body 171 is adapted to the outer contour shape of the conductive copper ring 123. Optionally, the toothed annular body 171 can be set as a polygonal ring or a circular ring, without specific limitation here.

[0061] The high-frequency system of particle accelerators requires high-precision closed-loop control, which requires real-time and accurate acquisition of the gap voltage signal of the magnetic alloy loading cavity 10. However, in the ultra-high gradient (100kV / m) environment, the traditional voltage acquisition structure is bulky. If it is installed inside the cavity, it will disrupt the field distribution. If it is installed outside the cavity, the traditional voltage acquisition structure cannot solve the high-voltage insulation problem in a compact space.

[0062] To solve the above problems, such as Figure 7 and Figure 8 As shown, the magnetic alloy high-frequency system provided in this embodiment also includes a voltage sampling module 50 disposed within the power transmission pipeline 30. The voltage sampling module 50 includes an L-shaped connecting copper busbar 51, a ceramic vacuum capacitor 52, and a metal shielding cap 53. One end of the L-shaped connecting copper busbar 51 is connected to the high-voltage end of the high-frequency transmission body 40, and the other end of the L-shaped connecting copper busbar 51 is connected to the high-voltage end of the ceramic vacuum capacitor 52. The metal shielding cap 53 is installed on the low-voltage end of the ceramic vacuum capacitor 52 and connected to the outer wall (ground potential) of the power transmission pipeline 30, serving to shield interference and provide mechanical support. Several high-frequency ceramic capacitors (not shown) connected in parallel are integrated into the internal space of the metal shielding cap 53. By moving the high-frequency voltage sampling module 50 into the power transmission pipeline 30 (atmospheric environment), intracavity interference is avoided, and the structure is compact and small.

[0063] It should be noted that this voltage sampling module 50 adopts the principle of capacitive voltage division, consisting of the high-voltage arm capacitor C. high and low-voltage arm capacitor C low Composed of series connections, it can convert high-frequency, high-voltage signals of tens of kilovolts into low-voltage signals (such as a few volts to tens of volts) acceptable to the control system, with an output voltage V. out With input high voltage V in The relationship between them is: That is, the partial pressure ratio.

[0064] Among them, the high-voltage arm capacitor (C) high The corresponding capacitor is a ceramic vacuum capacitor 52, with a capacitance of 50pF. It serves as the primary high-voltage bearer. Because its capacitance is much smaller than that of the low-voltage arm capacitor, according to the impedance voltage division principle, the vast majority of high-frequency high voltages (such as tens of thousands of volts) are carried by this ceramic vacuum capacitor 52. The ceramic vacuum capacitor 52 possesses extremely high withstand voltage characteristics and extremely low dielectric loss, making it very suitable for withstanding high-gradient electric fields in compact spaces without breakdown. It can effectively solve the high-voltage insulation problem in compact spaces.

[0065] Low-voltage arm capacitor (C) low This corresponds to several parallel high-frequency ceramic capacitors integrated within the metal shielding cap 53. For example, ten 5nF high-frequency ceramic capacitors can be selected and connected in parallel in an array. The total capacitance after parallel connection is 10 × 5nF = 50nF = 50000pF, used to divide the sampled signal. Based on the above parameters, the voltage division ratio is approximately: This achieves a voltage sampling ratio of 1000:1. This ratio can be flexibly adjusted by changing the number or capacitance of the high-frequency ceramic capacitors connected in parallel within the metal shielding cap 53 to meet the needs of control systems with different ranges.

[0066] Therefore, by adopting the voltage acquisition module described above, and utilizing the excellent insulation performance of the ceramic vacuum capacitor 52, high-voltage isolation is achieved within a very short axial distance. The 50pF capacitor bears the majority of the voltage, ensuring safety. The low-voltage side capacitors are cleverly arrayed and hidden inside the metal shielding cap 53, which not only utilizes the metal shielding cap 53 for electromagnetic shielding (preventing external stray signals from interfering with sampling accuracy) but also protects the fragile high-frequency ceramic capacitors. The structure is extremely compact, achieving modular integration. By adopting a hybrid dielectric voltage divider method of "ceramic vacuum capacitor 52 + high-frequency ceramic capacitor array", a high voltage division ratio of 1000:1 and high withstand voltage capability are achieved in a very small space, solving the closed-loop control sampling problem of the ultra-high gradient accelerator cavity.

[0067] In summary, the magnetic alloy high-frequency system provided in this embodiment can operate stably in an environment with ultra-high gradient (target 100kV / m). By improving the power supply structure, optimizing the insulation and sealing design, and adjusting the layout of the sampling module, arcing is effectively suppressed, and the system's withstand voltage and installation reliability are improved.

[0068] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A magnetic alloy high-frequency system, characterized in that, include: The magnetic alloy loading cavity (10) includes a cavity shell (11), an inner conductor assembly (12), a wall-penetrating assembly (14), and a feed electrode (15). The inner conductor assembly (12) is coaxially disposed inside the cavity shell (11). The wall-penetrating assembly (14) is sealed and connected to the periphery of the cavity shell (11). The feed electrode (15) passes through the wall-penetrating assembly (14) and is electrically connected to the inner conductor assembly (12). The feed electrode (15) is insulated from the wall-penetrating assembly (14). The number of the wall-penetrating assembly (14) and the feed electrode (15) are both set to two and are matched one-to-one. The two feed electrodes (15) are arranged at a 90° interval along the circumference of the cavity shell (11). The power source (20) is connected to the cavity shell (11) through a power transmission pipe (30). The power transmission pipe (30) is covered outside the wall-penetrating assembly (14). A high-frequency transmission body (40) corresponding to the feed electrode (15) is provided inside the power transmission pipe (30). One end of the high-frequency transmission body (40) is connected to the feed electrode (15), and the other end of the high-frequency transmission body (40) is connected to the power source (20).

2. The magnetic alloy high-frequency system according to claim 1, characterized in that, The interior of the inner conductor assembly (12) is a vacuum cavity (124). The inner conductor assembly (12) and the cavity shell (11) form two first cavities (111) and a second cavity (112) connected between the two first cavities (111). Both the first cavity (111) and the second cavity (112) are filled with insulating gas. The wall-penetrating assembly (14) can seal the second cavity (112). The feed electrode (15) is located inside the second cavity (112).

3. The magnetic alloy high-frequency system according to claim 2, characterized in that, The inner conductor assembly (12) includes a beam channel (121), a ceramic tube (122), and a conductive copper ring (123). Both ends of the ceramic tube (122) are connected to the conductive copper ring (123). The beam channel (121) is connected to both ends of the ceramic tube (122) through the conductive copper ring (123). The two feed electrodes (15) are electrically connected to different conductive copper rings (123).

4. The magnetic alloy high-frequency system according to claim 3, characterized in that, The bottom of the opposite sides of the second cavity (112) is provided with inner conductor walls (114), and the two inner conductor walls (114) are provided in correspondence with the two conductive copper rings (123). Each inner conductor wall (114) is connected to the corresponding conductive copper ring (123) by a feed copper bus (17), and the two feed electrodes (15) are respectively connected to different inner conductor walls (114).

5. The magnetic alloy high-frequency system according to claim 4, characterized in that, The power supply copper bus (17) includes a toothed annular body (171) and a plurality of copper bus bodies (172). The toothed annular body (171) is fixedly fitted on the conductive copper ring (123). The plurality of copper bus bodies (172) are arranged at intervals along the circumference of the toothed annular body (171). One end of the plurality of copper bus bodies (172) is connected to a plurality of teeth of the toothed annular body (171) in a corresponding manner. The other end of the plurality of copper bus bodies (172) is connected to the inner conductor wall (114).

6. The magnetic alloy high-frequency system according to claim 1, characterized in that, It also includes a voltage sampling module (50) disposed in the power transmission pipe (30). The voltage sampling module (50) includes an L-shaped connecting copper busbar (51), a ceramic vacuum capacitor (52) and a metal shielding cap (53). One end of the L-shaped connecting copper busbar (51) is connected to the high voltage end of the high frequency transmission body (40), and the other end of the L-shaped connecting copper busbar (51) is connected to the high voltage end of the ceramic vacuum capacitor (52). The metal shielding cap (53) is installed on the low voltage end of the ceramic vacuum capacitor (52) and connected to the outer wall of the power transmission pipe (30). Several high frequency ceramic capacitors connected in parallel are integrated in the internal space of the metal shielding cap (53).

7. The magnetic alloy high-frequency system according to claim 1, characterized in that, The through-wall assembly (14) includes a first ceramic plate (141) and a second ceramic plate (142) arranged coaxially. The feed electrode (15) passes through the first ceramic plate (141) and the second ceramic plate (142) in sequence. A sealed cavity (143) is formed between the first ceramic plate (141) and the second ceramic plate (142). The sealed cavity (143) is filled with a cooling medium. A medium inlet (144) is provided on one side of the sealed cavity (143), and a medium outlet (145) is provided on the other side of the sealed cavity (143).

8. The magnetic alloy high-frequency system according to claim 7, characterized in that, The outer periphery of the first ceramic piece (141) and the second ceramic piece (142) are brazed to the metal flange (147) through a metallization layer (146), and the metallization layer (146) together with the first ceramic piece (141) and the second ceramic piece (142) form the sealed cavity (143).

9. The magnetic alloy high-frequency system according to claim 7, characterized in that, At least one of the first ceramic sheet (141) and the second ceramic sheet (142) has a groove (148) formed on its surface to increase the creepage distance.

10. The magnetic alloy high-frequency system according to claim 7, characterized in that, The first ceramic sheet (141) and the second ceramic sheet (142) are high-purity, high-density alumina ceramics with a purity ≥99.5% and a density ≥3.90g / cm3; Alternatively, the first ceramic sheet (141) and the second ceramic sheet (142) may be aluminum nitride ceramic or beryllium oxide ceramic.

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