Electrode detachable four-wing type radio frequency quadrupole accelerator cavity

Abstract

This invention relates to a four-wing type radio frequency quadrupole accelerator cavity with detachable electrodes, comprising a cavity, electrodes, a sealing assembly, and an end plate, wherein the end of the cavity is open. The electrodes are disposed inside the cavity and are detachably connected to the cavity via fasteners. The sealing assembly seals the installation gap between the cavity and the electrodes, and the end plate seals the end of the cavity. Compared with existing technologies, in this invention, the electrodes are detachably connected to the cavity, resulting in a modular design. In practical use, when arcing causes electrode damage or beam contamination on the electrodes, leading to a decrease in the accelerator cavity's radio frequency performance, the user can quickly restore the accelerator's high-frequency performance by disassembling and replacing the electrodes, eliminating the need to rebuild the entire accelerator. Therefore, this accelerator cavity has the advantages of easy disassembly and replacement.

Description

Technical Field

[0001] This invention relates to the field of ion accelerator technology, and in particular to a four-wing type radio frequency quadrupole accelerator cavity with detachable electrodes. Background Technology

[0002] The radio frequency quadrupole (RFQ) accelerator is a new type of accelerator that integrates beam acceleration, focusing, and beam convergence. It is mainly suitable for accelerating low-energy beams and is generally used as an injector in medium- and high-energy accelerators.

[0003] During construction, the cavity walls and electrodes of a quadrupole RFQ accelerator are typically machined as a single piece. However, this method presents a significant problem: an inefficient overall structural design, leading to high construction costs. Specifically, the integral machining of the cavity walls and electrodes requires large blocks of oxygen-free copper, resulting in substantial waste of copper and increasing the construction cost of the RF quadrupole accelerator. For example, the China Spallation Neutron Source (SNS) accelerator in the United States experienced a significant decline in RF performance after nearly ten years of operation, necessitating a replacement in 2017. Each replacement cost between five and six million RMB. Similarly, the ADS Pilot Project Injector II RFQ accelerator at the Institute of Modern Physics, due to the integral machining of the cavity walls and electrodes, requires oxygen-free copper plates with a width of 370 mm for its vertical electrodes, while the actual width of the electrodes is less than 80 mm, resulting in significant copper waste. Therefore, optimizing the overall structure, constructing a low-cost quadrilateral RFQ cavity, and reducing the frequency of cavity replacement are particularly important for reducing the cost of accelerator projects. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes, which has the advantages of easy disassembly, assembly, and replacement.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes, comprising:

[0007] A cavity, wherein the ends of the cavity are open.

[0008] An electrode is disposed inside the cavity and is detachably connected to the cavity via fasteners.

[0009] A sealing assembly to seal the mounting gap between the cavity and the electrode;

[0010] An end plate that seals the end of the cavity.

[0011] Preferably, the cross-section of the detachable four-wing radio frequency quadrupole accelerator cavity is an N-sided polygon, where N is greater than 2. The cavity is divided into N cavity wall plates, which are welded or detachably connected to each other.

[0012] The number of electrodes corresponds to the number of cavity wall plates, and each electrode is mounted on its corresponding cavity wall plate, with the electrodes being centrally symmetrically distributed.

[0013] The aforementioned four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes is preferably equipped with a high-frequency seal.

[0014] The electrode has a first contact surface, which is engaged with the cavity wall plate, and the high-frequency seal is disposed on the first contact surface.

[0015] The described four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes is preferably provided in which the high-frequency seal includes a first sealing groove, the first sealing groove is formed on the first mating surface, and each electrode is provided with two first sealing grooves, the first sealing grooves being arranged along the length direction of the electrode.

[0016] On the same electrode, two first sealing grooves are respectively located on both sides of the fastener;

[0017] The high-frequency seal also includes a high-frequency spring corresponding to the first sealing groove, and the high-frequency spring is embedded in the first sealing groove.

[0018] The aforementioned four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes is preferably equipped with fasteners including bolts;

[0019] An end cap is provided on the cavity wall plate, and the bolt passes through the end cap and the corresponding cavity wall plate to be threadedly connected to the electrode.

[0020] The aforementioned four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes is preferably characterized by a vacuum seal as part of the sealing assembly.

[0021] The end cap has a second mating surface, which engages with the cavity wall plate, and the vacuum seal is disposed on the second mating surface.

[0022] The aforementioned four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes is preferably characterized in that the vacuum seal includes a second sealing groove and a sealing gasket.

[0023] The second sealing groove is disposed on the second mating surface and surrounds the bolt;

[0024] The sealing gasket is embedded in the second sealing groove.

[0025] Preferably, in the described four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes, the cavity wall plate has a transition portion, and the cavity wall plate is connected to the electrodes through the transition portion;

[0026] The transition section is in a fitted connection with the electrode.

[0027] Preferably, in the described four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes, the outer edge of the electrodes and the outer edge of the transition portion are smoothly transitioned.

[0028] Preferably, in the described four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes, the root of the transition section is provided with an inner chamfer.

[0029] The present invention has the following advantages due to the adoption of the above technical solutions:

[0030] Compared with existing technologies, the electrodes inside the accelerator cavity are detachably connected to the cavity, so the whole is a split design. In actual use, when the accelerator cavity’s radio frequency performance degrades due to arcing causing electrode damage or beam contamination on the electrodes, the user can quickly restore the accelerator’s high-frequency performance by disassembling and replacing the electrodes, without having to rebuild the entire accelerator. Therefore, this detachable four-wing radio frequency quadrupole accelerator cavity has the advantages of easy disassembly and easy replacement.

[0031] Meanwhile, the independent electrodes and cavity wall plates can be machined from smaller oxygen-free copper sheets, reducing waste of large, solid pieces of oxygen-free copper and significantly lowering the construction cost of the accelerator cavity. Furthermore, the independent structure of the electrodes and cavity wall plates allows them to be machined from different metals; for example, the electrodes can be made of oxygen-free copper while the cavity wall plates can be made of stainless steel or aluminum. Ultimately, this reduces the material cost of the accelerator cavity without increasing the probability of arcing, making its overall structural design highly practical. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the specific structure of the cavity in one embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the internal structure of the cavity in one embodiment of the present invention;

[0034] Figure 3 yes Figure 2 Enlarged view of point A in the middle;

[0035] Figure 4 This is a schematic diagram of the specific structure of a fastener in one embodiment of the present invention.

[0036] The markings in the diagram are as follows:

[0037] 10. Cavity; 101. Cavity wall plate; 102. Transition section; 1021. Third mating surface; 103. Inner chamfer; 104. Rounded corner;

[0038] 20. Electrode; 201. First bonding surface;

[0039] 30. End plate;

[0040] 40. Fastener; 41. End cap; 411. Second mating surface;

[0041] 50. First sealing groove; 51. Second sealing groove. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," "third," "fourth," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0044] Currently, existing accelerator cavities have unreasonable structural designs, making subsequent disassembly, replacement, and maintenance difficult. To address these technical problems, this invention provides a four-wing type radio frequency quadrupole accelerator cavity with detachable electrodes, which has the advantages of easy disassembly and replacement.

[0045] The technical solution of the present invention will be described in detail below with reference to specific examples.

[0046] Reference Figure 1 , Figure 2 as well as Figure 3As shown, the present invention provides a four-wing type radio frequency quadrupole accelerator cavity with detachable electrodes, comprising a cavity 10, electrodes 20, a sealing assembly, and an end plate 30, wherein the end of the cavity 10 is open. Electrodes 20 are disposed inside the cavity 10 and are detachably connected to the cavity 10 by fasteners 40. The sealing assembly seals the installation gap between the cavity 10 and the electrodes 20, and the end plate 30 seals the end of the cavity 10.

[0047] It should be noted that in this embodiment, the cavity 10 is arranged in a sleeve shape, the electrode 20 is arranged inside the cavity 10, and there are two end plates 30. The two end plates 30 are used to seal the two ends of the cavity 10 respectively to achieve the sealing of the cavity 10.

[0048] Compared with existing technologies, the electrode 20 is detachably connected to the cavity 10 inside the accelerator cavity, so the whole is a split design. In actual use, when arcing causes damage to the electrode 20 or the beam causes contamination on the electrode 20, resulting in a decrease in the radio frequency performance of the accelerator cavity, the user can quickly restore the high frequency performance of the accelerator by disassembling and replacing the electrode 20, without having to rebuild the entire accelerator. Therefore, this detachable four-wing radio frequency quadrupole accelerator cavity has the advantages of easy disassembly and replacement.

[0049] Meanwhile, the independent electrodes 20 and cavity 10 can be machined from small-volume oxygen-free copper plates, thus reducing the waste of large, solid pieces of oxygen-free copper and significantly lowering the construction cost of the accelerator cavity. Furthermore, the independent structure of the electrodes 20 and cavity 10 allows them to be machined from different metal materials; for example, the electrodes 20 can be made of oxygen-free copper while the cavity 10 can be made of stainless steel or aluminum. Ultimately, this reduces the material cost of the accelerator cavity without increasing the probability of arcing, making its overall structural design highly practical.

[0050] In one embodiment, the cavity 10 is further refined, with an N-sided cross-section where N is greater than 2. The cavity 10 is divided into N cavity wall plates 101, which are welded or detachably connected to each other. The number of electrodes 20 corresponds to the number of cavity wall plates 101, and each electrode 20 is mounted on its corresponding cavity wall plate 101, exhibiting a centrally symmetrical distribution.

[0051] The number of cavity wall plates 101 and electrodes 20 is related to the actual required accelerator parameters. In this embodiment, the cross-section of the cavity 10 can be a regular quadrilateral or a regular octagon. For ease of illustration, the cross-section of the cavity 10 in this embodiment is a regular quadrilateral. The cavity 10 is provided with four cavity wall plates 101, and adjacent cavity wall plates 101 are welded together. At the same time, four electrodes 20 are also provided, each electrode 20 is installed on a corresponding cavity wall plate 101, and the electrodes 20 are arranged horizontally or vertically.

[0052] The separate design of cavity 10 can further optimize the structural design of the accelerator cavity, resulting in a better overall structural assembly effect. In the initial stage, cavity 10 is assembled by welding, and then the electrode 20 is installed on the corresponding cavity wall plate 101 by fastener 40. It has a high degree of assembly flexibility.

[0053] In one embodiment, the sealing assembly is further refined, including a high-frequency seal. The electrode 20 has a first contact surface 201 that engages with the cavity wall plate 101, and the high-frequency seal is disposed on the first contact surface 201.

[0054] The high-frequency seal includes a first sealing groove 50, which is formed on the first mating surface 201. Two first sealing grooves 50 are correspondingly provided on each electrode 20, and the first sealing grooves 50 are arranged along the length direction of the electrode 20. On the same electrode 20, the two first sealing grooves 50 are located on opposite sides of the fastener 40. The high-frequency seal also includes a high-frequency spring corresponding to the first sealing groove 50, which is embedded within the first sealing groove 50 to achieve a sealing effect. This high-frequency sealing method ensures the continuity of the surface current on the inner wall of the cavity 10 and maintains the complete radio frequency characteristics of the cavity.

[0055] Reference Figure 3 as well as Figure 4 As shown, in this embodiment, the fastener 40 includes a bolt, and an end cap 41 is provided on the cavity wall plate 101. The bolt passes through the end cap 41 and the corresponding cavity wall plate 101 and is threadedly connected to the electrode 20. It should be noted that in this embodiment, the end cap 41 is specifically a vacuum end cap 41.

[0056] Meanwhile, the sealing assembly also includes a vacuum seal. The end cap 41 has a second mating surface 411, which engages with the cavity wall plate 101. The vacuum seal is disposed on the second mating surface 411. The vacuum seal includes a second sealing groove 51 and a sealing gasket. The second sealing groove 51 is disposed on the second mating surface 411 and surrounds the bolt. The sealing gasket is correspondingly embedded in the second sealing groove 51.

[0057] In a further detailed embodiment, to optimize the sealing effect of the end plate 30, both high-frequency sealing and vacuum sealing are also provided on the end plate 30. This ensures the integrity of the high-frequency sealing and vacuum sealing of the entire cavity 10.

[0058] In one embodiment, the cavity wall plate 101 is further refined. In this embodiment, the cavity wall plate 101 has a transition portion 102, through which the cavity wall plate 101 is connected to the electrode 20. The transition portion 102 is in a bonding connection with the first contact surface 201. Specifically, the transition portion 102 has a third contact surface 1021, and the first contact surface 201 and the third contact surface 1021 are bonded together.

[0059] Furthermore, the outer edge of electrode 20 and the outer edge of transition portion 102 are smoothly transitioned. Specifically, the outer edge of electrode 20 and the outer edge of transition portion 102 are flush. This ensures the continuity and smoothness of the transition.

[0060] More preferably, in this embodiment, the root of the transition portion 102 is provided with an inner chamfer 103, and the connection between adjacent cavity wall plates 101 is also provided with a smooth transition, wherein one side of the transition is provided with a fillet 104. The provision of the inner chamfer 103 and the fillet 104 can further reduce the processing material, thereby reducing material usage.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes, characterized in that, include: The cavity has an open end; the cross-section of the cavity is an N-sided polygon, where N is 4 or 8; the cavity is divided into N cavity wall panels, which are welded or detachably connected to each other. An electrode is disposed inside the cavity, the number of which corresponds to the cavity wall plate, and each electrode is respectively mounted on a corresponding cavity wall plate, the electrodes being centrally symmetrically distributed; the electrode is detachably connected to the cavity by fasteners; the fasteners include bolts, and an end cap is provided on the cavity wall plate, the bolt passing through the end cap and the corresponding cavity wall plate and being threadedly connected to the electrode; A sealing assembly to seal the mounting gap between the cavity and the electrode; End plate, the end plate sealing the end of the cavity The sealing assembly includes a high-frequency seal; The electrode has a first contact surface, which is engaged with the cavity wall plate, and the high-frequency seal is disposed on the first contact surface; The high-frequency seal includes a first sealing groove, which is formed on the first mating surface. Each electrode is provided with two first sealing grooves, which are arranged along the length of the electrode. On the same electrode, two first sealing grooves are respectively located on both sides of the fastener; The high-frequency seal also includes a high-frequency spring corresponding to the first sealing groove, and the high-frequency spring is embedded in the first sealing groove.

2. The four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes according to claim 1, characterized in that, The sealing assembly includes a vacuum seal; The end cap has a second mating surface, which engages with the cavity wall plate, and the vacuum seal is disposed on the second mating surface.

3. The four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes according to claim 1, characterized in that, The vacuum seal includes a second sealing groove and a sealing gasket; The second sealing groove is disposed on the second mating surface and surrounds the bolt; The sealing gasket is embedded in the second sealing groove.

4. The four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes according to claim 1, characterized in that, The cavity wall plate has a transition portion, and the cavity wall plate is connected to the electrode through the transition portion; The transition section is in a fitted connection with the electrode.

5. The four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes according to claim 4, characterized in that, The outer edge of the electrode and the outer edge of the transition portion are smoothly transitioned.

6. The four-wing-shaped radio frequency quadrupole accelerator cavity with detachable electrodes according to claim 4, characterized in that, The root of the transition section is provided with an inner chamfer.

Images