Cyclotron high-frequency structure without outer lining
By using a non-cladding design to form a continuous conductive layer by plating copper on the surface of the cyclotron's magnetic poles, the problems of space occupation and increased mechanical difficulty caused by the outer cladding structure are solved, thereby achieving improved acceleration efficiency and reduced costs.
Patent Information
- Application Number
- CN202510883020.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-28
- Publication Date
- 2025-11-04
AI Technical Summary
In existing cyclotron high-frequency cavity designs, the outer liner structure occupies valuable space, hindering the increase of the accelerating electrode angle and the improvement of acceleration efficiency, while also increasing the difficulty of mechanical design and the requirements for mechanical fit tolerances.
The design adopts a non-outer liner design, with copper directly plated on the surface of the cyclotron magnetic poles as the outer conductor of the high-frequency cavity, forming a continuous conductive layer of the main magnetic pole concave and convex surface integrated structure. This eliminates the need for an independent outer liner, utilizes the concave and convex surface of the magnetic poles to free up space, increases the angle of the accelerating electrodes, and facilitates the installation of auxiliary components.
It saves installation space and mechanical design complexity, improves acceleration efficiency, reduces manufacturing costs, simplifies the installation process, and avoids complex magnetic pole shape matching requirements.
Smart Images
Figure CN120897315A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of high-frequency cavity of cyclotron, and particularly relates to a high-frequency structure of cyclotron without outer lining. BACKGROUND
[0002] The high-frequency cavity is one of the core components of the cyclotron, and provides the energy source for the acceleration of particles. The structural design of the high-frequency cavity has a crucial influence on the layout of the accelerator, especially for the compact cyclotron. The simpler the structure is, the lower the requirement for the size of the accelerator chamber is, and the manufacturing cost can be greatly reduced.
[0003] The current mainstream high-frequency cavity of the cyclotron is a coaxial double-conductor structure, which includes an inner conductor and an outer conductor, and the outer conductor is also called an outer lining. The high-frequency cavity structure with a separate outer lining design has a high-frequency loss P loss which is mainly concentrated on the acceleration electrode (inner conductor) and the outer lining. Since the outer lining is used, the power loss P loss is low. As can be seen from formula (1), when the power loss P loss is low, the high-frequency cavity has a high quality factor Q. If the outer lining structure is not used, the overall loss P loss is high due to the influence of the magnetic core loss, plating loss and surface roughness, and the Q value is low.
[0004]
[0005] In the formula, f is the frequency, W is the stored energy, P loss is the loss, and Q is the quality factor.
[0006] Although the design of the outer lining can obtain a high quality factor, for the compact cyclotron, the design of the outer lining makes the high-frequency system structure more complex, directly affects the spatial structure layout of the cyclotron and the manufacturing cost, and limits the development of the compact cyclotron. The main manifestations are as follows:
[0007] (1) The high-frequency cavity is mainly installed in the valley area opposite to the magnetic pole. The design scheme of the separate outer lining will occupy the valuable space of the valley area, so that the opening angle θ of the acceleration electrode matched with the shape of the valley area is reduced. According to the acceleration principle of the accelerator, under the condition of a given harmonic number h = 4, between 0-45 degrees, the larger the opening angle is, the higher the acceleration efficiency is, and the greater the maximum energy gain of the particles per cycle is. The design scheme with the outer lining occupies the space to some extent, and hinders the increase of the opening angle of the acceleration electrode and the improvement of the acceleration efficiency.
[0008]
[0009] (2) In order to ensure the stable operation of the high-frequency system, the high-frequency cavity needs to be equipped with corresponding key auxiliary components such as RF couplers and tuners. For the high-frequency cavity with an outer liner, the fixed installation of the auxiliary components described above needs to pass through the outer liner structure, increasing the difficulty of mechanical design. In contrast, the high-frequency cavity without an outer liner can avoid the above problems.
[0010] (3) The outer liner structure needs to be designed and installed to match the magnetic pole shape, and the stability needs to be considered during installation, and the requirement for mechanical fit tolerance is relatively high. In contrast, the design without an outer liner can save these considerations.
[0011] In summary, the high-frequency cavity design with an outer liner occupies the valuable space of the valley, hindering the increase of the accelerating electrode angle and the improvement of the accelerating efficiency; the high-frequency cavity design with an outer liner makes the fixed installation of auxiliary components need to pass through the outer liner structure, increasing the difficulty of mechanical design; and the high-frequency cavity design with an outer liner requires the outer liner structure to match the magnetic pole shape for design and installation, and has a relatively high requirement for mechanical fit tolerance. SUMMARY
[0012] The present application aims to solve the problems existing in the prior art, and proposes a high-frequency structure of a cyclotron without an outer liner. The first purpose is to solve the problem that the high-frequency cavity design with an outer liner occupies the valuable space of the valley, hindering the increase of the accelerating electrode angle and the improvement of the accelerating efficiency; the second purpose is to solve the problem that the high-frequency cavity design with an outer liner makes the fixed installation of auxiliary components need to pass through the outer liner structure, increasing the difficulty of mechanical design; and the third purpose is to solve the problem that the high-frequency cavity design with an outer liner requires the outer liner structure to match the magnetic pole shape for design and installation, and has a relatively high requirement for mechanical fit tolerance.
[0013] The present application adopts the following technical means to solve the technical problems:
[0014] A high-frequency cavity structure of a cyclotron without an outer liner, the high-frequency cavity structure comprising an inner liner structure and an outer liner structure, characterized in that: the outer liner structure is no longer designed as a separate triangular outer liner structure, but a high-frequency cavity outer liner structure based on the main magnetic pole concave-convex surface connection is formed by directly plating copper on the surface of the magnetic pole of the cyclotron as the outer conductor of the high-frequency cavity to form a continuous conductive layer, and the high-frequency inner conductor is placed in the symmetrical magnetic pole valley to form a complete high-frequency cavity structure with the high-frequency cavity outer liner structure based on the main magnetic pole concave-convex surface connection; the high-frequency cavity outer liner structure based on the main magnetic pole concave-convex surface connection is used to release the space occupied by the original each high-frequency cavity outer liner, and the released space is used to increase the electrode angle of the inner liner structure of the high-frequency cavity and improve the accelerating efficiency, and facilitates the barrier-free installation of the auxiliary components of the high-frequency cavity.
[0015] Further, the copper plating on the surface of the cyclotron magnetic pole directly as the outer conductor of the high-frequency cavity includes plating copper on all visible surfaces of each magnetic pole protruding and recessing on both sides of the accelerator center plane.
[0016] Further, the copper plating on all visible surfaces of each magnetic pole protruding on both sides of the accelerator center plane, that is, plating copper on three surfaces of each magnetic pole, which are the upper surface of each magnetic pole and the two side surfaces of each magnetic pole.
[0017] Further, the copper plating on all visible surfaces of each magnetic pole recessing on both sides of the accelerator center plane, that is, plating copper on the upper surface of the recessed valley between the magnetic poles.
[0018] Further, the copper plating on all visible surfaces of each magnetic pole protruding and recessing on both sides of the accelerator center plane has a thickness greater than 10 times the skin depth.
[0019] Further, the inner lining structure of the high-frequency cavity includes inner rods (1-1), Dee plates (1-2), and center electrodes (2); the inner rods (1-1) and the Dee plates (1-2) are connected at the tail to form an integral whole, which is divided into left and right inner rods (1-1) and Dee plates (1-2); the left and right inner rods (1-1) are respectively arranged on the upper and lower sides of the respective intermediate connecting plates (11) and connected by bolts; the center line of the intermediate connecting plate (11) is provided with a water cooling channel, and a water needle (9) is installed in the water cooling channel; the left and right inner rods (1-1) are electrically connected by the center electrode (2) as a bridge; the center electrode (2) is composed of two upper and lower parts and is fixed and supported by a Puller (6); the inner sides of the left and right Dee plates (1-2) are pre-buried and welded with circular copper pipes (12), and the tail four corners are provided with coarse adjustment blocks (3) for cavity tuning; the coaxial part of the inner rod (1-1) is provided with a symmetrical outer cylinder (4) and a end face flange (7) fixed connection; the outer surface of the outer cylinder (4) is welded with an outer cylinder water cooling spiral copper pipe (5), and the end face flange (7) is provided with an end face water cooling copper pipe (8); one side of the end face flange (7) is provided with a coupler (14), and the outer sides of the respective symmetrical outer cylinders (4) are provided with Pick up sampling rings (15).
[0020] Advantages and effects of the present application
[0021] 1. The outer lining structure is cancelled, the installation space of the cyclotron is saved, the structural complexity and installation difficulty are reduced, and the processing cost is saved.
[0022] 2. Significant results were achieved by changing the position and shape of the high-frequency cavity liner: the liner shape changed from a closed triangular shape representing a single high-frequency cavity to a continuous conductive layer with the main magnetic poles of the entire accelerator as the unit, featuring a concave-convex shape. This concave-convex shape was achieved by directly plating copper onto the surface of the cyclotron magnetic poles as the outer conductor of the high-frequency cavity. This freed up valuable space in each magnetic pole valley region, allowing for an increase in the angle θ of the accelerating electrodes that matches the valley shape, thus improving acceleration efficiency. Furthermore, it eliminated the need for auxiliary components of each high-frequency cavity to pass through the liner structure during installation, significantly saving installation time. It also avoided the hassle of matching complex magnetic pole shapes during mechanical fabrication of the liner. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of a high-frequency cavity structure with an external liner, as shown in the prior art.
[0024] Figure 2 This invention relates to a copper-plated, continuous conductive layer forming a concave-convex surface outer liner structure for the main magnetic poles.
[0025] Figure 3 This is a first-view perspective of the high-frequency cavity liner structure without an outer liner of the present invention.
[0026] Figure 4 This is a second perspective view of the high-frequency cavity liner structure without an outer liner of the present invention.
[0027] 1-1: Inner rod; 1-2: 2: Center electrode; 3: Coarse adjustment block; 4: Outer cylinder; 5: Outer cylinder water-cooled spiral copper tube; 6: Puller; 7: End face flange; 8: End face water-cooled copper tube; 9: Water-transporting needle; 10: A fixing screw; 11: Intermediate connecting plate; 12: Electrode water-cooled copper tube; 13: B fixing screw; 14: Coupler; 15: Pick up. Detailed Implementation
[0028] Design principle of the invention
[0029] 1. The innovation of the present application: By changing the position and shape of the outer lining of the high-frequency cavity, outstanding results are achieved: the shape of the outer lining is changed from the original closed triangular shape of a single high-frequency cavity to the shape of the main magnetic pole of the entire accelerator, which is a continuous conductive layer of the main magnetic pole concave-convex shape, and this main magnetic pole concave-convex shape is realized by directly plating copper on the surface of the cyclotron magnetic pole as the outer conductor of the high-frequency cavity. The advantages of this are: first, the valuable space of each magnetic pole valley is liberated, which increases the opening angle θ of the accelerating electrode matching the shape of the valley, and the larger the opening angle, the higher the acceleration efficiency; second, since the outer lining structure of each high-frequency cavity is removed, each high-frequency cavity auxiliary component can be installed directly without passing through the outer lining structure, which greatly saves the engineering installation time; the outer lining structure is plated with copper, avoiding the trouble of matching the complex magnetic pole shape when the outer lining is mechanically made.
[0030] 2. Design principle of the outer lining-free high-frequency structure: In this embodiment, the main magnetic pole convex surface (two sides and one surface of each magnetic pole of the main magnetic pole), concave surface all need to be plated with copper. First, the significance of plating copper on the side surface of the main magnetic pole is that the side surface and the inner lining of the high-frequency cavity electrode form an acceleration gap, without which particles cannot be accelerated. Therefore, the inner lining of the two high-frequency cavities forms four accelerator gaps with the plated copper on the adjacent side surface of the main magnetic pole; second, the significance of plating copper on the surface and concave surface of the main magnetic pole is that since the outer lining of each independent high-frequency cavity is removed, the entire accelerator space has an electric field rather than just the high-frequency electrode acceleration gap, so a shielding shell needs to be added to all places with an electric field. The difference between copper plating and non-copper plating lies in that the electrical conductivity of copper is high, the power loss P loss is small, and if the main magnetic pole is not plated with copper, the electrical conductivity of the magnetic pole iron is lower than that of copper, the power loss P loss is relatively large, according to formula (1), when the power loss P loss is relatively large, the quality factor Q is relatively small. Before the improvement, the outer lining of each high-frequency cavity is independent and closed, so the electric field outside the outer lining of each high-frequency cavity is weak and does not need shielding, but after the improvement, the outer lining of each high-frequency cavity is removed, so the surface, concave surface, and side surface of the main magnetic pole all need to be plated with copper for overall shielding, which is equivalent to making a large outer lining for the two high-frequency cavities, changing from independent outer lining to shared outer lining.
[0031] The present application will be further explained in conjunction with the accompanying drawings:
[0032] An outer lining-free cyclotron high-frequency cavity structure is shown in Figures 2-4As shown, the high-frequency cavity structure includes an inner lining structure and an outer lining structure, and is characterized in that: the outer lining structure is no longer designed as a separate triangular outer lining structure, but is formed as a high-frequency cavity outer lining structure based on a main magnetic pole concave-convex surface connection by directly plating copper on the surface of the cyclotron magnetic pole as the outer conductor of the high-frequency cavity, forming a continuous conductive layer, and placing the high-frequency inner conductor in the symmetrical magnetic pole valley region to form a complete high-frequency cavity structure with the high-frequency cavity outer lining structure based on the main magnetic pole concave-convex surface connection; the high-frequency cavity outer lining structure based on the main magnetic pole concave-convex surface connection is used to release the space originally occupied by each high-frequency cavity outer lining, and the released space is used to increase the electrode opening angle on the inner lining structure of the high-frequency cavity, thereby improving the acceleration efficiency, and facilitating the unobstructed installation of high-frequency cavity auxiliary components.
[0033] Supplementary Note 1
[0034] The triangular outer lining structure before improvement is as shown in Figure 1 The outer lining structure formed by plating copper after improvement is as shown in Figure 2 In fact, the outer lining formed by plating copper is very thin, only more than 10 times the skin depth, and cannot be taken down alone but is attached to the concave-convex surface of the main magnetic pole of the accelerator. In order to facilitate understanding, the physical shape formed by plating copper is expressed as Figure 2
[0035] As shown in Figure 2 The cyclotron magnetic pole surface is directly plated with copper as the outer conductor of the high-frequency cavity, including plating copper on all visible surfaces of each magnetic pole protruding upward and downward on both sides of the accelerator center plane.
[0036] As shown in Figure 2 The copper plating on all visible surfaces of each magnetic pole protruding upward and downward on both sides of the accelerator center plane is copper plating on three surfaces of each magnetic pole, which are the upper surface of each magnetic pole and the two side surfaces of each magnetic pole.
[0037] As shown in Figure 2 The copper plating on all visible surfaces of each magnetic pole protruding upward and downward on both sides of the accelerator center plane is copper plating on the upper surface of the valley region between the magnetic poles.
[0038] As shown in Figure 2 The copper plating on all visible surfaces of each magnetic pole protruding upward and downward on both sides of the accelerator center plane is copper plating on three surfaces of each magnetic pole, which are the upper surface of each magnetic pole and the two side surfaces of each magnetic pole.
[0039] As shown in Figure 3 , Figure 4 As shown, the inner lining structure of the high frequency cavity comprises inner rods 1-1, Dee plates 1-2 and a center electrode 2; the inner rods 1-1 and the Dee plates 1-2 are connected at the tail to form an integral whole and are divided into left and right inner rods 1-1 and Dee plates 1-2; the left and right inner rods 1-1 are respectively arranged on the upper and lower sides of the respective intermediate connecting plates 11 and are connected by bolts; the center line of the intermediate connecting plate 11 is provided with a water cooling channel, and a water needle 9 is additionally arranged in the water cooling channel; the left and right inner rods 1-1 are electrically connected through the center electrode 2 as a bridge; the center electrode 2 is composed of two upper and lower plates and is fixed and supported by a puller 6; the inner sides of the left and right Dee plates 1-2 are pre-buried and welded with circular copper pipes 12, and the tail four corners are provided with coarse adjustment blocks 3 for cavity tuning; the coaxial part of the inner rod 1-1 is provided with a symmetrical outer cylinder 4 which is fixedly connected with an end face flange 7; the outer surface of the outer cylinder 4 is welded with an outer cylinder water cooling spiral copper pipe 5, and the end face flange 7 is provided with an end face water cooling copper pipe 8; one side of the end face flange 7 is provided with a coupler 14, and the respective outer sides of the symmetrical outer cylinders 4 are respectively provided with pick up sampling rings 15.
[0040] It should be emphasized that the above specific embodiments are merely an explanation of the present application and are not a limitation of the present application, and those skilled in the art can make modifications to the above embodiments without creative contribution after reading the present specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.
Claims
1. A linerless cyclotron high-frequency cavity structure, comprising an inner liner structure and an outer liner structure, characterized in that: Instead of designing a separate triangular outer liner structure, this new outer liner structure uses copper plating directly on the surface of the cyclotron's magnetic poles as the outer conductor of the high-frequency cavity, forming a continuous conductive layer. This structure is based on the main magnetic pole's concave-convex surface and is integrated with the high-frequency cavity outer liner structure. The high-frequency inner conductor is placed in the symmetrical magnetic pole valley region, forming a complete high-frequency cavity structure with the main magnetic pole's concave-convex surface integrated high-frequency cavity outer liner structure. This high-frequency cavity outer liner structure based on the main magnetic pole's concave-convex surface integrated high-frequency cavity outer liner structure is used to release the space occupied by each high-frequency cavity outer liner in the original way. The released space is used to increase the electrode angle on the inner liner structure of the high-frequency cavity, improve acceleration efficiency, and facilitate the unobstructed installation of high-frequency cavity auxiliary components.
2. The linerless cyclotron high-frequency cavity structure according to claim 1, characterized in that: The method of directly plating copper on the surface of the cyclotron magnetic poles as the outer conductor of the high-frequency cavity includes plating copper on all visible surfaces, both protruding and recessed, of each magnetic pole on both sides of the accelerator's central plane.
3. The linerless cyclotron high-frequency cavity structure according to claim 2, characterized in that: The process of plating copper on all visible surfaces protruding from each magnetic pole on both sides of the accelerator's central plane means plating copper on three surfaces of each magnetic pole: the upper surface and the two side surfaces.
4. The linerless cyclotron high-frequency cavity structure according to claim 2, characterized in that: The copper plating on all visible surfaces of the recessed areas of each magnetic pole on both sides of the accelerator's central plane refers to copper plating on the upper surface of the recessed valley areas between the magnetic poles.
5. The linerless cyclotron high-frequency cavity structure according to claim 2, characterized in that: The copper plating is applied to all visible surfaces, both protruding and recessed, of each magnetic pole on both sides of the accelerator's central plane, with a thickness greater than 10 times the skin depth.
6. The linerless cyclotron high-frequency cavity structure according to claim 2, characterized in that: The lining structure of the high-frequency cavity includes an inner rod (1-1), a Dee plate (1-2), and a center electrode (2); the inner rod (1-1) and the tail of the Dee plate (1-2) are connected as a whole, and are divided into left and right parts, the inner rod (1-1) and the Dee plate (1-2); the left and right parts of the inner rod (1-1) are respectively placed on the upper and lower sides of their respective intermediate connecting plates (11) and are connected by bolts; a water-cooling channel is left in the center line of the intermediate connecting plate (11), and a water-cooling needle (9) is installed in the water-cooling channel; the left and right parts of the inner rod (1-1) are electrically connected by the center electrode (2) as a bridge; the center electrode (2) It consists of two parts, upper and lower, which are fixed and supported by Puller (6); the inner side of the left and right Dee plates (1-2) is pre-embedded with welded circular copper tubes (12), and the four corners of the tail are equipped with coarse adjustment blocks (3) for cavity tuning; the coaxial part with the inner rod (1-1) is provided with a symmetrical outer cylinder (4) and fixedly connected to the end face flange (7); the outer surface of the outer cylinder (4) is welded with an outer cylinder water-cooled spiral copper tube (5), and the end face flange (7) is provided with an end face water-cooled copper tube (8); one side of the end face flange (7) is provided with a coupler (14), and each of the symmetrical outer cylinders (4) is provided with a Pickup sampling ring (15).