Radio frequency quadrupole accelerator for multiple vacuum applications

Abstract

This invention relates to the field of particle acceleration technology, and provides a radio frequency quadrupole accelerator for multiple vacuum scenarios. The accelerator includes a radio frequency cavity and a vacuum cover. The cavity wall of the radio frequency cavity has grid holes for evacuation. The vacuum cover is detachably installed at the grid hole location. When the vacuum cover is installed at the grid hole location, it maintains a vacuum environment within the radio frequency cavity in independent vacuum applications. When the vacuum cover is detached from the grid hole location, it places the radio frequency cavity within a vacuum chamber in integrated vacuum applications. This invention, by providing evacuation channels through grid holes in the cavity wall of the radio frequency cavity, eliminates the need for the welded vacuum flange structure of existing radio frequency cavity walls, effectively reducing the lateral dimensions of the radio frequency cavity and thus its volume, enabling miniaturized accelerator design. Furthermore, the grid hole structure effectively reduces the impact of the vacuum channels on the radio frequency performance of the radio frequency cavity.

Description

Technical Field

[0001] This invention relates to the field of particle acceleration technology, and in particular to a radio frequency quadrupole accelerator for multi-vacuum applications. Background Technology

[0002] The Radio Frequency Quadrupole (RFQ) is a crucial component of particle accelerator technology, primarily used to accelerate low-energy particle beams (typically ion beams) from a direct current (DC) state to sufficiently high energy levels. The RFQ cavity must perform the focusing, convergence, and acceleration processes from a DC beam to a clump. To ensure beam transmission efficiency, the RFQ cavity needs to maintain a high or even ultra-high vacuum internally to stabilize the beam quality. Furthermore, a strong electric field exists within the RFQ cavity; if the vacuum level is insufficient, residual gas molecules can cause ionization discharge, known as "RF breakdown." Therefore, high and ultra-high vacuums ensure the electromagnetic field within the RFQ cavity remains strong without frequent RF breakdown.

[0003] Accelerator technology has stringent requirements regarding size and installation conditions for applications in medicine, proton-excited X-ray fluorescence spectroscopy, and other fields, which has driven the miniaturization of accelerators. However, existing radio frequency quadrupole accelerators are relatively large and difficult to install in limited spaces. Therefore, there is an urgent need to develop miniaturization technology for radio frequency quadrupole accelerators. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a radio frequency quadrupole accelerator for multiple vacuum scenarios, thereby reducing the peripheral volume of the radio frequency cavity and achieving miniaturization of the accelerator.

[0005] This invention provides a radio frequency quadrupole accelerator for multi-vacuum applications, comprising:

[0006] A radio frequency cavity, wherein the cavity wall of the radio frequency cavity is provided with grid holes for vacuuming;

[0007] A vacuum cover plate is detachably installed at the grid hole position; when the vacuum cover plate is installed at the grid hole position, it is used to maintain a vacuum environment in the radio frequency cavity in an independent vacuum application scenario; when the vacuum cover plate is detached from the grid hole position, it is used to place the radio frequency cavity in a vacuum chamber in an integrated vacuum application scenario.

[0008] According to an embodiment of the present invention, a radio frequency quadrupole accelerator for multiple vacuum scenarios is provided. The outer wall of the radio frequency cavity has a first receiving groove for accommodating the vacuum cover plate. The first side of the vacuum cover plate has a vacuum groove communicating with the grid hole. The second side of the vacuum cover plate has a connecting flange communicating with the vacuum groove.

[0009] According to an embodiment of the present invention, a radio frequency quadrupole accelerator for multiple vacuum scenarios is provided, wherein the grid aperture includes a plurality of elongated apertures arranged side by side along the beam direction, and the long side of the elongated apertures is perpendicular to the beam direction.

[0010] According to an embodiment of the present invention, a radio frequency quadrupole accelerator for multi-vacuum scenarios is provided. The radio frequency cavity includes a plurality of cavity wall plates connected end to end, and the inner wall of the cavity wall plate has a wing plate extending toward the center of the radio frequency cavity.

[0011] According to an embodiment of the present invention, a radio frequency quadrupole accelerator for multiple vacuum scenarios is provided, wherein the plurality of cavity wall plates include a first half-cavity wall plate, a first intermediate wall plate, a second half-cavity wall plate, and a second intermediate wall plate connected end to end; the grid holes are disposed on the first half-cavity wall plate and the second half-cavity wall plate;

[0012] The wing plates of the first half-cavity wall panel, the first intermediate wall panel, the second half-cavity wall panel, and the second intermediate wall panel are evenly distributed circumferentially.

[0013] According to an embodiment of the present invention, a radio frequency quadrupole accelerator for multi-vacuum scenarios is provided. The cross-section of the radio frequency cavity is octagonal. The first half-cavity wall plate and the second half-cavity wall plate have three connected cavity walls. The cavity wall located in the middle is connected to the wing plate, and the cavity walls located on both sides are provided with the grid holes.

[0014] According to an embodiment of the present invention, a radio frequency quadrupole accelerator for multi-vacuum scenarios is provided, wherein the grid holes of all cavity wall plates are arranged in a centrally symmetrical manner.

[0015] According to an embodiment of the present invention, a radio frequency quadrupole accelerator for multi-vacuum scenarios is provided, wherein the first half-cavity wall plate has a tuner port and a sampling port.

[0016] According to an embodiment of the present invention, a radio frequency quadrupole accelerator for multi-vacuum scenarios is provided, wherein the second half-cavity wall plate has a tuner port and a sampling port.

[0017] According to an embodiment of the present invention, a radio frequency quadrupole accelerator for multi-vacuum scenarios is provided, which further includes a connecting component, wherein a first end of the connecting component is connected to an end of the radio frequency cavity, and a second end of the connecting component has a connector.

[0018] According to an embodiment of the present invention, a radio frequency quadrupole accelerator for multi-vacuum scenarios is provided, wherein the connector has a connecting part and a positioning part.

[0019] The radio frequency quadrupole accelerator for multi-vacuum applications provided in this invention provides a vacuum channel by creating grid holes in the cavity wall of the radio frequency cavity. In independent vacuum applications, a vacuum cover is installed at the grid hole location to maintain a vacuum environment within the radio frequency cavity. In integrated vacuum applications, the vacuum cover is removed from the grid hole location to allow the radio frequency cavity to be placed within a vacuum chamber for compact accelerator system integration. Furthermore, the existing welded vacuum flange structure of the radio frequency cavity wall is eliminated, reducing the lateral dimension of the radio frequency cavity by approximately 27%, thereby reducing the volume of the radio frequency cavity and enabling miniaturized accelerator design. In addition, compared to the circular vacuum channel of a welded vacuum flange, the grid hole structure reduces the longitudinal non-uniformity of the electric field in the radio frequency quadrupole accelerator by approximately 67%, effectively reducing the impact of the vacuum channel on the radio frequency performance of the radio frequency cavity. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an existing radio frequency cavity.

[0021] Figure 2 This is one of the structural schematic diagrams of a radio frequency quadrupole accelerator for multi-vacuum scenarios provided in the embodiments of the present invention.

[0022] Figure 3 This is the second schematic diagram of the structure of the radio frequency quadrupole accelerator for multi-vacuum scenarios provided in the embodiments of the present invention.

[0023] Figure 4 This is an exploded schematic diagram of the radio frequency cavity provided in an embodiment of the present invention.

[0024] Figure 5 This is one of the structural schematic diagrams of the cavity wall plate provided in the embodiments of the present invention.

[0025] Figure 6 This is the second schematic diagram of the cavity wall plate provided in the embodiment of the present invention.

[0026] Figure 7 This is a schematic diagram illustrating the influence of different vacuum structures on the longitudinal flatness of the electric field, obtained by finite element electromagnetic simulation software provided in this embodiment of the invention.

[0027] Figure 8 This is a schematic diagram of the structure of the sealing part of the end face of the radio frequency quadrupole accelerator for multi-vacuum scenarios provided in the embodiments of the present invention.

[0028] The attached figures are labeled as follows:

[0029] 1. Radio frequency cavity; 11. First half-cavity wall panel; 12. First intermediate wall panel; 13. Second half-cavity wall panel; 14. Second intermediate wall panel; 15. Grid hole; 16. First receiving groove; 17. Tuner port; 18. Sampling port; 19. Second sealing groove;

[0030] 2. Wing plate;

[0031] 3. End cap;

[0032] 4. Connecting components;

[0033] 5. Vacuum cover plate; 51. Connecting flange. Detailed Implementation

[0034] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0035] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0037] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0039] The following is combined with Figures 2-8 This invention describes a radio frequency quadrupole accelerator for multi-vacuum scenarios.

[0040] Embodiments of the present invention propose a radio frequency quadrupole accelerator for multi-vacuum applications, such as... Figures 2 to 6 As shown, the radio frequency quadrupole accelerator for multi-vacuum applications includes a radio frequency cavity 1 and a vacuum cover 5; the cavity wall of the radio frequency cavity 1 has a grid hole 15 for evacuation; the vacuum cover 5 is detachably installed at the grid hole 15 position; when the vacuum cover 5 is installed at the grid hole 15 position, it is used to maintain a vacuum environment inside the radio frequency cavity 1 in an independent vacuum application scenario; when the vacuum cover 5 is removed from the grid hole 15 position, it is used to place the radio frequency cavity 1 in a vacuum chamber in an integrated vacuum application scenario.

[0041] It is understandable that the cavity wall of the radio frequency cavity 1 is provided with a grid hole 15 for vacuuming, so as to provide a channel for vacuuming the radio frequency cavity 1. The grid hole 15 serves as a channel for gas migration during the vacuuming process of the radio frequency cavity 1.

[0042] It should be noted that in existing technologies, such as Figure 1 As shown, a knife-edge flange is provided on the end face of the RF cavity 1. The knife-edge flange has a lateral dimension. Therefore, compared with the existing knife-edge flange, the grid hole 15 of the present invention can effectively reduce the lateral dimension of the RF cavity 1. Furthermore, the present invention disperses the existing large concentrated taps into smaller grid holes 15, which can reduce the impact of the vacuum structure on RF performance (field uniformity and quality factor).

[0043] The radio frequency quadrupole accelerator for multi-vacuum applications provided in this invention provides a vacuum channel by opening a grid hole 15 in the cavity wall of the radio frequency cavity 1. In independent vacuum applications, a vacuum cover is installed at the grid hole position to maintain a vacuum environment inside the radio frequency cavity. In integrated vacuum applications, the vacuum cover is removed from the grid hole position to place the radio frequency cavity inside a vacuum chamber for compact accelerator system integration. It also eliminates the need for the welded vacuum flange structure of the existing radio frequency cavity 1 cavity wall, effectively reducing the lateral dimension of the radio frequency cavity 1, thereby reducing the volume of the radio frequency cavity 1 and achieving miniaturized accelerator design. In addition, the grid hole 15 can effectively reduce the impact of the vacuum channel structure on the radio frequency performance of the radio frequency cavity 1.

[0044] According to an embodiment of the present invention, a removable vacuum cover plate 5 is provided at the grid hole 15 position of the radio frequency cavity 1. The vacuum cover plate 5 is installed at the grid hole 15 position of the radio frequency cavity 1 to achieve sealing of the inner cavity of the radio frequency cavity 1. Alternatively, the vacuum cover plate 5 can be removed and placed in a vacuum chamber for compact accelerator system integration. Thus, the radio frequency quadrupole accelerator of this embodiment, applicable to multiple vacuum scenarios, can be used in multiple scenarios.

[0045] Optionally, the outer wall of the radio frequency cavity 1 has a first receiving groove 16 for accommodating the vacuum cover plate 5, the first side of the vacuum cover plate 5 has a vacuum groove communicating with the grid hole 15, and the second side of the vacuum cover plate 5 has a connecting flange 51 communicating with the vacuum groove.

[0046] It is understandable that a first receiving groove 16 is provided at the grid hole 15 position of the RF cavity 1 to seal the grid hole 15 when the vacuum cover plate 5 is installed in the first receiving groove 16. At the same time, a vacuum groove is provided on the first side of the vacuum cover plate 5. When the vacuum cover plate 5 is installed in the first receiving groove 16, the vacuum groove of the vacuum cover plate 5 communicates with the grid hole 15. A connecting flange 51 is provided on the second side of the vacuum cover plate 5, and the connecting flange 51 communicates with the vacuum groove. When the vacuum pump is connected to the connecting flange 51, the vacuum pump evacuates the RF cavity 1 through the inner cavity of the connecting flange 51, the vacuum groove, and the grid hole 15. In this way, a removable vacuum cover plate 5 is provided at the grid hole 15 position of the cavity wall. The RF cavity 1 can generally be equipped with an external vacuum pump, or the vacuum cover plate 5 on the cavity wall can be removed and placed in a vacuum chamber to achieve vacuuming of the RF cavity 1, thus enabling application in multiple scenarios.

[0047] Understandably, in the case of independent vacuum use of the RF cavity 1, vacuum blind flanges and vacuum transition flanges can be installed at the grid aperture locations for mounting molecular pumps or vacuum pipelines. In the case of integrated vacuum use, after the vacuum blind flanges or vacuum transition flanges are removed, the RF cavity 1 can be placed in a vacuum chamber for compact accelerator system integration. It should be noted here that the vacuum transition flange is the structure with a connecting flange 51 integrated on the vacuum cover plate 5; the RF cavity 1 has multiple grid apertures arranged circumferentially, and vacuum blind flanges can be installed in some of the grid apertures, while vacuum transition flanges can be installed in others.

[0048] It should be noted that the miniaturization of the accelerator not only requires the miniaturization of the radio frequency cavity 1, but also simplifies its auxiliary equipment. In this embodiment, the cavity wall is provided with grid holes 15 for vacuuming, and after removing the vacuum cover plate 5, the radio frequency cavity 1 can be placed in the vacuum chamber, which can effectively reduce the number and volume of vacuum auxiliary components.

[0049] It should be noted that the biggest contradiction and constraint in the design of the RF cavity 1 is the conflict between the reduction of its structural size and the layout of its RF structure (such as the mode separation structure) and auxiliary structures (such as the vacuum extraction port and sampling port 18). However, in this embodiment, the RF cavity 1 is placed in a vacuum chamber, which can largely solve or avoid these contradictions and constraints in the miniaturization of the RF cavity 1.

[0050] In the embodiments of the present invention, the lateral dimension (diameter) of the RF cavity 1 is less than 140 mm, which is ~20 mm smaller than the existing unoptimized RFQ RF cavity 1 structure at the same resonant frequency (~160 mm). Furthermore, RF simulation and multiphysics analysis show that the RF cavity 1 of the present invention does not affect the RF loss and quality factor of the cavity when applied in various scenarios. It should be noted that the longitudinal non-uniformity of the electromagnetic field can be adjusted by modifying the structure of the RF cavity 1.

[0051] In one embodiment of the present invention, a first receiving groove 16 is provided at the location of the grid hole 15 in the cavity wall, and a screw hole is provided on the first receiving groove 16 located on the outer periphery of the grid hole 15. The vacuum cover plate 5 is disposed in the first receiving groove 16. Correspondingly, the vacuum cover plate 5 is provided with a connecting hole that mates with the threaded hole. By passing a bolt through the connecting hole and the threaded hole in sequence, the vacuum cover plate 5 is disposed in the first receiving groove 16 of the cavity wall to seal the grid hole 15. When the radio frequency cavity 1 is placed in the vacuum chamber, the bolts and the vacuum cover plate 5 on the cavity wall are removed.

[0052] It is understandable that the cavity wall has a first receiving groove 16. When processing the cavity wall, the raw materials of the radio frequency cavity 1 corresponding to the first receiving groove 16, such as copper, are omitted, thereby reducing the cost of raw materials.

[0053] Furthermore, to improve the sealing performance between the vacuum cover 5 and the cavity wall, a sealing ring is provided between the vacuum cover 5 and the first receiving groove 16. In this embodiment, the sealing ring is a rubber ring, eliminating the need for a welded knife-edge flange, thereby reducing the cavity volume.

[0054] In one embodiment of the present invention, the grid aperture 15 includes a plurality of elongated apertures arranged side by side along the beam direction, wherein the long side of the elongated apertures is perpendicular to the beam direction.

[0055] Understandably, the same cavity wall of the RF cavity 1 has multiple elongated holes arranged side-by-side along the beam direction, which form a grid aperture 15. It should be noted that the number and size of the elongated holes can be rationally designed according to the vacuum requirements of the RF cavity 1. For example, for an RF cavity 1 placed in a vacuum chamber, the number of elongated holes in its grid aperture 15 can be appropriately increased; for an RF cavity 1 that does not need to be placed in a vacuum chamber, the number of elongated holes in its grid aperture 15 is determined based on the effective tap area.

[0056] For example, the RF cavity 1 is provided with four grid holes 15, which are arranged circumferentially along the RF cavity 1. Each grid hole 15 includes 11 elongated holes arranged along the beam direction (i.e., longitudinal direction). The long side of the elongated holes is perpendicular to the beam direction. The distance L1 between two adjacent elongated holes is 10 mm, and the length L2 of the elongated hole along the longitudinal direction is 5 mm. The two ends of the elongated holes along the long side are semi-circular, and the straight section L3 between the two semi-circular ends of the elongated hole is 20 mm. It should be noted that if there is interference from process holes, the length of the elongated holes can be changed.

[0057] In one embodiment of the present invention, the radio frequency cavity 1 includes a plurality of cavity wall plates connected end to end to form a cavity. The cavity wall plates are provided with grid holes 15 for vacuuming. The inner wall of the cavity wall plates has wing plates 2 extending toward the center of the radio frequency cavity 1. The vacuum cover plate 5 is detachably disposed at the grid hole 15 position of the cavity wall plate.

[0058] It is understandable that the radio frequency cavity 1 is surrounded by multiple cavity wall plates, and a wing plate 2 is connected to the inner wall of the cavity wall plate. The wing plate 2 and the cavity wall plate are processed as a whole to reduce the error caused by the assembly and welding between the wing plate 2 and the cavity wall plate.

[0059] It should be noted that in the prior art, the knife-edge flange and the RF cavity 1 are connected by welding, which easily causes deformation of the RF cavity 1. However, the embodiment of the present invention provides a vacuum channel by opening grid holes 15 in the cavity wall plate, eliminating the need for the existing vacuum flange structure and effectively reducing the volume of the RF cavity 1; and by integrally connecting the wing plate 2 to the cavity wall plate, the wing plate 2 and the cavity wall plate are processed as a whole, which can reduce the error caused by welding and assembly of the wing plate 2 and the cavity wall plate, and thus avoid the defect of reduced RF performance of the RF cavity 1 caused by the weld between the wing plate 2 and the cavity wall plate.

[0060] In one embodiment of the present invention, a higher operating frequency is used, which can be selected in the range of 650 MHz to 1 GHz, depending on existing radio frequency power source products.

[0061] The radio frequency cavity 1 includes four cavity wall plates, and the radio frequency cavity 1 is composed of four parts, specifically including a first half-cavity wall plate 11, a first intermediate wall plate 12, a second half-cavity wall plate 13 and a second intermediate wall plate 14 connected end to end, and grid holes 15 are opened on the first half-cavity wall plate 11 and the second half-cavity wall plate 13.

[0062] Each cavity wall panel is connected to a wing plate 2, and the number of wing plates 2 is the same as the number of cavity wall panels. Therefore, the radio frequency cavity 1 has four wing plates 2, which are respectively connected to four cavity wall panels. The wing plates 2 and the cavity wall panels are integrally formed. Specifically, the four wing plates 2 are integrally connected to the first half-cavity wall panel 11, the first intermediate wall panel 12, the second half-cavity wall panel 13, and the second intermediate wall panel 14, respectively.

[0063] After the first half-cavity wall plate 11, the first intermediate wall plate 12, the second half-cavity wall plate 13, and the second intermediate wall plate 14 are connected end to end, the four wing plates 2 located in the cavity are uniformly arranged around the same circumference with the center of the radio frequency cavity 1 as the center; and the end of the wing plate 2 near the center of the radio frequency cavity 1 has an electrode, so the electrode centers of the four wing plates 2 are symmetrically arranged in the radio frequency cavity 1.

[0064] For example, if the electrode, wing plate 2, and cavity wall plate are machined as a whole, then the electrode, wing plate 2, and cavity wall plate are integrally machined parts.

[0065] Furthermore, the cross-section of the RF cavity 1 is octagonal. The first half-cavity wall plate 11 is designated as the upper half-cavity wall plate, the first intermediate wall plate 12 as the left intermediate wall plate, the second half-cavity wall plate 13 as the lower half-cavity wall plate, and the second intermediate wall plate 14 as the right intermediate wall plate. The left intermediate wall plate is located between the left end of the upper half-cavity wall plate and the left end of the lower half-cavity wall plate, and the right intermediate wall plate is located between the right end of the upper half-cavity wall plate and the right end of the lower half-cavity wall plate. It should be noted that up, down, left, and right are defined as the orientation when looking from the beam inlet to the beam outlet of the RF cavity 1.

[0066] The upper and lower cavity walls each have three connected cavity walls, and the left and right middle walls each have one cavity wall. Thus, the upper, left, lower, and right middle walls are connected end to end to form an octagonal radio frequency cavity 1. The cavity walls in the middle of the upper and lower cavity walls are connected to wing plates 2, and grid holes 15 are provided on the cavity walls on both sides of the upper and lower cavity walls.

[0067] Preferably, when the dimensions of each cavity wall of the upper and lower cavity walls are the same as the dimensions of the cavity walls of the left and right middle walls, the cross-section of the radio frequency cavity 1 is a regular octagon.

[0068] According to an embodiment of the present invention, the grid holes 15 on all cavity walls are arranged in a centrally symmetrical manner. The grid holes 15 are arranged periodically in the longitudinal direction, with the grid holes 15 on the four cavity walls symmetrically arranged at the same longitudinal position in the beam direction. This arrangement avoids the disturbance to the electric field in the central region of the beam channel caused by the introduction of the grid holes 15, and ensures the uniformity of the electric field along the circumference.

[0069] It should be noted that even if the introduction of the grid aperture 15 causes a slight disturbance to the longitudinal distribution of the electric field in the central region of the beam channel, it can be adjusted by fine-tuning the cavity RF structure and by tuning after the RF cavity 1 is fabricated.

[0070] In one embodiment of the invention, the first half-cavity wall plate 11 has a tuner port 17 and a sampling port 18.

[0071] For example, the first half-cavity wall panel 11 has tuner ports 17 located on both sides of the grid aperture 15 along the beam direction, and a sampling port 18 located between one of the tuner ports 17 and the grid aperture 15. Of course, the second half-cavity wall panel 13 also has tuner ports 17 and sampling ports 18, so the first half-cavity wall panel 11 and the second half-cavity wall panel 13 have the same structure.

[0072] Furthermore, threaded holes are provided around the tuner port 17 of the first half-cavity wall plate 11 and the second half-cavity wall plate 13 to facilitate the connection of the tuner to the tuner port 17 by bolts; and threaded holes are also provided around the sampling port 18 of the first half-cavity wall plate 11 and the second half-cavity wall plate 13 to facilitate the connection of the sampling ring to the sampling port 18 by bolts.

[0073] In one embodiment of the present invention, a connecting component 4 is provided at both ends of the radio frequency cavity 1. The first end of the connecting component 4 is connected to the end of the radio frequency cavity 1, and the second end of the connecting component 4 has a connector. The connector is used to connect the radio frequency cavity 1 to the end cover 3, and the connector is also used to connect two radio frequency cavities 1.

[0074] Optionally, the connecting component 4 can be a connecting jacket; specifically, the connecting component 4 includes multiple L-shaped connecting plates, the number of L-shaped connecting plates is equal to the number of cavity wall plates, and their positions correspond one-to-one. One side of the multiple L-shaped connecting plates is connected to the outer wall of the end of the multiple cavity wall plates, and the other side of the L-shaped connecting plates faces away from the center of the RF cavity 1. The other side of the L-shaped connecting plates serves as a connector.

[0075] Furthermore, the connector has a connecting portion. For example, a threaded hole is provided on the other side of the L-shaped connecting plate to serve as the connecting portion; preferably, the other side of the L-shaped connecting plate also has a positioning portion for positioning when the RF cavity 1 is connected to the end cover 3 or when two RF cavities 1 are connected. The positioning portion can be a positioning hole or a positioning protrusion.

[0076] In this embodiment, the end cap 3 is bolted to the end face of the first half-cavity wall plate 11 and the end face of the second half-cavity wall plate 13, and a second sealing groove 19 is provided on the end face of the first half-cavity wall plate 11 and the end face of the second half-cavity wall plate 13, so as to arrange a sealing element in the second sealing groove 19 to improve the sealing performance of the connection between the end cap 3 and the radio frequency cavity 1; and a connecting jacket is provided between the end cap 3 and the end face of the radio frequency cavity 1.

[0077] It should be noted that a mounting groove is provided at the tuner port 17 position of the cavity wall plate to form a sealing plane. When installing the tuner, the mounting groove forms a positioning groove for the tuner, and a sealing element can be installed in the mounting groove to improve the sealing performance of the tuner connection. Of course, a corresponding mounting groove is also provided at the sampling port 18 position of the cavity wall plate.

[0078] In one specific embodiment of the present invention, the radio frequency quadrupole accelerator for multi-vacuum scenarios includes a radio frequency cavity 1 and a vacuum cover plate 5.

[0079] The radio frequency cavity 1 includes a first half-cavity wall plate 11, a first intermediate wall plate 12, a second half-cavity wall plate 13, and a second intermediate wall plate 14. The first half-cavity wall plate 11 and the second half-cavity wall plate 13 each have three connected cavity walls, and the first intermediate wall plate 12 and the second intermediate wall plate 14 each have one cavity wall. The first half-cavity wall plate 11, the first intermediate wall plate 12, the second half-cavity wall plate 13, and the second intermediate wall plate 14 are connected end to end to form a radio frequency cavity 1 with a regular octagonal cross-section.

[0080] The RF cavity 1 also includes four wing plates 2. The first half-cavity wall plate 11 and the second half-cavity wall plate 13 are respectively connected to the cavity wall between them. The first intermediate wall plate 12 and the second intermediate wall plate 14 are respectively connected to the wing plates 2. The wing plates 2 connected to the first half-cavity wall plate 11 and the second half-cavity wall plate 13 are arranged vertically. The first half-cavity wall plate 11 and its upper wing plate 2 form the upper vertical wing, the second half-cavity wall plate 13 and its upper wing plate 2 form the lower vertical wing, the first intermediate wall plate 12 and its upper wing plate 2 form the left horizontal wing, and the second intermediate wall plate 14 and its upper wing plate 2 form the right horizontal wing. The first half-cavity wall plate 11 and its upper wing plate 2 are machined as a single piece, and the second half-cavity wall plate 13 and its upper wing plate 2 are also machined as a single piece. This can reduce the errors caused by component assembly and welding. At the same time, the reduction of assembly and welding can avoid the problem of RF performance degradation of the RF cavity 1 caused by weld seams. Of course, the first intermediate wall panel 12 and the wing plate 2, as well as the second intermediate wall panel 14 and the wing plate 2, can all be integrally processed.

[0081] Grid holes 15 are provided on the cavity walls on both sides of the first half-cavity wall plate 11 and the cavity walls on both sides of the second half-cavity wall plate 13. The cavity walls with grid holes 15 are inclined, and these cavity walls are referred to as inclined surfaces. Grid holes 15 are provided on the cavity walls (inclined surfaces) of the four quadrants of the RF cavity 1 to provide channels for vacuuming the RF cavity 1. At the same time, through RF simulation and structural design, the grid holes 15 have no effect on the quality factor and shunt impedance of the RF cavity 1. Through the adjustment and design of the RF structure, the flatness and symmetry of the RF electric field in the beam channel region are ensured to meet the design requirements of beam dynamics.

[0082] A vacuum cover plate 5 is provided at the grid hole 15 position of the cavity wall plate, and the vacuum cover plate 5 is detachably connected to the cavity wall plate. When the vacuum cover plate 5 is connected to the cavity wall plate, the radio frequency quadrupole accelerator for multi-vacuum scenarios in this embodiment can be installed without being placed in the vacuum chamber and can be independently tested and operated by installing a vacuum pump group, just like a traditional accelerator system. Alternatively, the vacuum cover plate 5 on the cavity wall plate can be removed and placed in the vacuum chamber for integrated use as a compact accelerator system.

[0083] The welding surface is the junction of the straight and oblique edges of the cavity wall near the left and right horizontal wings. The solder groove is located on the welding plane of the horizontal wings (left and right horizontal wings) and the welding plane of the lower vertical wing. The two vertical wings (upper and lower vertical wings) are machined as a whole in a CNC machining center, which reduces the error caused by the assembly of the octagonal wall panel (cavity wall panel) and the wing plate 2.

[0084] like Figure 1 and Figure 2As shown, the lateral dimensions of the RF cavity 1 in this embodiment are compared with those of the traditional RFQ RF cavity 1 structure. The lateral dimension B of the RF cavity 1 in this embodiment is 138.24 mm, which is 27% smaller than the lateral dimension A of 190 mm in the traditional structure. This reduces the amount of material used and has considerable application prospects in the field of miniaturization.

[0085] The radio frequency quadrupole accelerator for multi-vacuum applications provided in this embodiment of the invention uses a grid hole 15 in the cavity wall plate and a vacuum cover plate 5 detachably disposed at the grid hole 15 in the cavity wall plate as a vacuum sealing structure. This eliminates the structure of the current vacuum brazing flange, reduces the volume of auxiliary equipment, eliminates the tuner inaccuracy caused by the copper gasket of the knife-edge flange, and avoids the assembly difficulties of flange bolts caused by the compact structure.

[0086] The radio frequency quadrupole accelerator for multi-vacuum scenarios provided in this embodiment of the invention provides a channel for gas molecule migration during vacuuming by grid holes 15 on the cavity wall plate. Compared with the vacuum channel of the knife flange, the grid holes 15 have a larger cross-sectional area for the pumping channel, which is more conducive to achieving the high vacuum or even ultra-high vacuum requirements inside the radio frequency cavity 1.

[0087] like Figure 7 As shown, curve a indicates that no vacuum hole is opened in the cavity wall, curve b indicates that a circular vacuum hole (the vacuum hole of the existing connecting knife-edge flange) is opened in the cavity wall, and curve c indicates that a grid hole 15 is opened in the cavity wall in this embodiment. By comparing the longitudinal flatness of the electric field using different vacuum holes, it can be seen that the grid hole 15 structure in this embodiment has almost no effect on the longitudinal flatness of the electric field, while the use of a circular vacuum hole has a great impact on the longitudinal flatness of the electric field and exceeds the range required by beam dynamics.

[0088] like Figure 8 As shown, in this embodiment, the end cap 3 is connected to the end of the RF cavity 1, and a second sealing groove 19 is provided on the end face of the first half-cavity wall plate 11 and the end face of the second half-cavity wall plate 13, so as to arrange a sealing element in the second sealing groove 19 to improve the sealing performance of the connection between the end cap 3 and the RF cavity 1; and a connecting jacket is provided between the end cap 3 and the end face of the RF cavity 1. The end face sealing structure of the RF cavity 1 in this embodiment adopts a vacuum sealing groove, which, compared with the knife flange sealing structure, integrates the CF200 stainless steel knife flange, greatly reducing the structural volume and complexity of the RFQ RF cavity 1. At the same time, compared with the knife flange structure, the rubber ring vacuum sealing groove structure eliminates the problem of a large number of bolt installations and is more convenient to install.

[0089] 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 radio frequency quadrupole accelerator for multi-vacuum applications, characterized in that, include: Radio frequency cavity (1), the cavity wall of the radio frequency cavity (1) is provided with grid holes (15) for vacuuming. A vacuum cover (5) is detachably installed at the grid hole (15) position; when the vacuum cover (5) is installed at the grid hole (15) position, it is used to maintain a vacuum environment inside the radio frequency cavity (1) in an independent vacuum use scenario; when the vacuum cover (5) is detached from the grid hole (15) position, it is used to place the radio frequency cavity (1) in a vacuum chamber in an integrated vacuum use scenario.

2. The radio frequency quadrupole accelerator for multi-vacuum scenarios according to claim 1, characterized in that, The outer wall of the radio frequency cavity (1) has a first receiving groove (16) for accommodating the vacuum cover plate (5), the first side of the vacuum cover plate (5) has a vacuum groove communicating with the grid hole (15), and the second side of the vacuum cover plate (5) has a connecting flange (51) communicating with the vacuum groove.

3. The radio frequency quadrupole accelerator for multi-vacuum scenarios according to claim 1, characterized in that, The grid aperture (15) includes a plurality of elongated apertures arranged side by side along the beam direction, wherein the long side of the elongated aperture is perpendicular to the beam direction.

4. The radio frequency quadrupole accelerator for multi-vacuum scenarios according to any one of claims 1 to 3, characterized in that, The radio frequency cavity (1) includes a plurality of cavity wall plates connected end to end, and the inner wall of the cavity wall plates has a wing plate (2) extending toward the center of the radio frequency cavity (1).

5. The radio frequency quadrupole accelerator for multi-vacuum scenarios according to claim 4, characterized in that, The plurality of cavity wall panels include a first half-cavity wall panel (11), a first intermediate wall panel (12), a second half-cavity wall panel (13), and a second intermediate wall panel (14) connected end to end; the grid holes (15) are disposed on the first half-cavity wall panel (11) and the second half-cavity wall panel (13); The wing plates (2) of the first half-cavity wall panel (11), the wing plates (2) of the first intermediate wall panel (12), the wing plates (2) of the second half-cavity wall panel (13) and the wing plates (2) of the second intermediate wall panel (14) are evenly distributed in the circumferential direction.

6. The radio frequency quadrupole accelerator for multi-vacuum scenarios according to claim 5, characterized in that, The cross-section of the radio frequency cavity (1) is octagonal. The first half-cavity wall plate (11) and the second half-cavity wall plate (13) have three connected cavity walls. The cavity wall in the middle is connected to the wing plate (2), and the cavity walls on both sides are provided with the grid holes (15).

7. The radio frequency quadrupole accelerator for multi-vacuum scenarios according to claim 5, characterized in that, The grid holes (15) of all cavity wall plates are arranged in a centrally symmetrical manner.

8. The radio frequency quadrupole accelerator for multi-vacuum scenarios according to claim 5, characterized in that, The first half-cavity wall panel (11) has a tuner port (17) and a sampling port (18), and / or, The second half-cavity wall panel (13) has a tuner port (17) and a sampling port (18).

9. The radio frequency quadrupole accelerator for multi-vacuum scenarios according to claim 4, characterized in that, It also includes a connecting component (4), the first end of which is connected to the end of the radio frequency cavity (1), and the second end of which has a connector.

10. The radio frequency quadrupole accelerator for multi-vacuum scenarios according to claim 9, characterized in that, The connector has a connecting part and a positioning part.

Images