Radio frequency quadrupole field accelerator applied to multiple vacuum scenes

Abstract

The invention relates to the technical field of particle acceleration, and provides a radio frequency quadrupole field accelerator applied to multiple vacuum scenarios, the accelerator comprises a radio frequency cavity and a vacuum cover plate, the cavity wall of the radio frequency cavity is provided with grid holes used for vacuumizing, the vacuum cover plate is detachably installed at the grid holes, and the vacuum cover plate is detachably installed at the grid holes under the condition that the vacuum cover plate is installed at the grid holes. The vacuum module is used for maintaining a vacuum environment in the radio frequency cavity in an independent vacuum use scene; and under the condition that the vacuum cover plate is detached from the grid holes, the radio frequency cavity is arranged in the vacuum chamber in an integrated vacuum use scene. According to the invention, the grid holes are formed in the cavity wall of the radio frequency cavity to provide a hole channel for vacuumizing the radio frequency cavity, a welded vacuum flange structure of the cavity wall of the existing radio frequency cavity is omitted, and the transverse size of the radio frequency cavity is effectively reduced, so that the volume of the radio frequency cavity is reduced, and the miniaturization design of the accelerator is realized; in addition, the grid hole structure can effectively reduce the influence of the vacuum hole channel on the radio frequency performance of the radio frequency cavity.

Description

Technical Field

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

[0002] Radio Frequency Quadrupole (RFQ) is an important component of particle accelerator technology. It is mainly used to accelerate low-energy particle beams (usually ion beams) from a DC state to a sufficiently high energy level. The RF accelerator cavity needs to complete the bunching, focusing and acceleration process from DC beam to bunch. In order to ensure the transmission efficiency of the particle beam, the RF accelerator cavity needs to maintain a high vacuum or even an ultra-high vacuum inside it so that the beam quality of the beam remains stable. In addition, there is a strong electric field inside the RF accelerator cavity. If the vacuum inside the cavity is not high enough, the residual gas molecules may cause ionization discharge, which is the so-called "RF breakdown". Therefore, high vacuum and ultra-high vacuum can keep the electromagnetic field in the RF accelerator cavity at a high intensity without frequent RF breakdown.

[0003] The application of accelerator technology in medical treatment, proton induced X-ray fluorescence spectroscopy analysis, etc. has strict requirements on size and installation conditions, which has promoted the development of accelerators in the direction of miniaturization. However, the existing radio frequency quadrupole accelerator is large in size and difficult to install in a limited space. Therefore, it is urgent to develop miniaturization technology for radio frequency quadrupole accelerators. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a radio frequency quadrupole field accelerator for multi-vacuum scene applications to reduce the peripheral volume of the radio frequency cavity and achieve miniaturization of the accelerator.

[0005] The present invention provides a radio frequency quadrupole field accelerator for multi-vacuum scene applications, comprising: A radio frequency cavity, wherein the cavity wall of the radio frequency cavity is provided with grid holes for vacuuming; A vacuum cover plate is detachably mounted at the grid hole position; when the vacuum cover plate is mounted at the grid hole position, it is used to maintain a vacuum environment in the RF cavity in an independent vacuum usage scenario; when the vacuum cover plate is detached from the grid hole position, it is used to place the RF cavity in a vacuum chamber in an integrated vacuum usage scenario.

[0006] According to an embodiment of the present invention, a radio frequency quadrupole field accelerator for multi-vacuum scene applications is provided, wherein the outer wall of the radio frequency cavity has a first accommodating groove for accommodating the vacuum cover plate, the first side of the vacuum cover plate has a vacuum groove connected to the grid hole, and the second side of the vacuum cover plate has a connecting flange, and the connecting flange is connected to the vacuum groove.

[0007] According to a radio frequency quadrupole field accelerator for multi-vacuum scene applications provided by an embodiment of the present invention, the grid holes include a plurality of long strip holes arranged side by side along the beam direction, and the long side direction of the long strip holes is perpendicular to the beam direction.

[0008] According to an embodiment of the present invention, a radio frequency quadrupole field accelerator for multi-vacuum scene applications is provided, wherein the radio frequency cavity comprises a plurality of cavity wall plates connected end to end in sequence, and the inner walls of the cavity wall plates have wing plates extending toward the center of the radio frequency cavity.

[0009] According to an embodiment of the present invention, a radio frequency quadrupole field accelerator for multi-vacuum scene applications is provided, wherein the plurality of cavity wall plates include a first half cavity wall plate, a first middle wall plate, a second half cavity wall plate, and a second middle wall plate connected end to end in sequence; the grid holes are arranged on the first half cavity wall plate and the second half cavity wall plate; The wing plates of the first half-cavity wall plate, the wing plates of the first middle wall plate, the wing plates of the second half-cavity wall plate and the wing plates of the second middle wall plate are evenly distributed in the circumferential direction.

[0010] According to an embodiment of the present invention, a radio frequency quadrupole field accelerator for multi-vacuum scene applications is provided, wherein 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.

[0011] According to a radio frequency quadrupole field accelerator for multi-vacuum scene applications provided by an embodiment of the present invention, the grid holes of all cavity wall plates are arranged in a centrally symmetrical manner.

[0012] According to a radio frequency quadrupole field accelerator for multi-vacuum scene applications provided by an embodiment of the present invention, the first half-cavity wall plate has a tuner port and a sampling port.

[0013] According to a radio frequency quadrupole field accelerator for multi-vacuum scene applications provided by an embodiment of the present invention, the second half cavity wall plate has a tuner port and a sampling port.

[0014] A radio frequency quadrupole field accelerator for multi-vacuum scene applications provided according to an embodiment of the present invention also includes a connecting component, a first end of the connecting component is connected to the end of the radio frequency cavity, and a second end of the connecting component has a connector.

[0015] According to a radio frequency quadrupole field accelerator for multiple vacuum scene applications provided by an embodiment of the present invention, the connecting piece comprises a connecting portion and a positioning portion.

[0016] The radio frequency quadrupole accelerator for multiple vacuum scenario applications provided by an embodiment of the present invention provides a channel for evacuating the radio frequency cavity by opening a grid hole in the cavity wall of the radio frequency cavity. In an independent vacuum usage scenario, the vacuum cover is installed at the grid hole position to maintain a vacuum environment in the radio frequency cavity; in an integrated vacuum usage scenario, the vacuum cover is disassembled at the grid hole position to place the radio frequency cavity in a vacuum chamber for compact accelerator system integration; and the welded vacuum flange structure of the existing radio frequency cavity wall is eliminated, so that the lateral size of the radio frequency cavity is reduced by about 27%, thereby reducing the volume of the radio frequency cavity to achieve a miniaturized design of the accelerator; in addition, compared with the circular hole vacuum channel of the welded vacuum flange, the grid hole structure reduces the longitudinal unevenness of the electric field of the radio frequency quadrupole accelerator by about 67%, which can effectively reduce the influence of the vacuum channel on the radio frequency performance of the radio frequency cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of an existing radio frequency cavity.

[0018] Figure 2 This is one of the structural schematic diagrams of the radio frequency quadrupole field accelerator for multi-vacuum scene applications provided by an embodiment of the present invention.

[0019] Figure 3 This is the second structural schematic diagram of the radio frequency quadrupole field accelerator for multi-vacuum scene applications provided by an embodiment of the present invention.

[0020] Figure 4 It is an exploded schematic diagram of the radio frequency cavity provided by an embodiment of the present invention.

[0021] Figure 5 It is one of the structural schematic diagrams of the cavity wall plate provided in the embodiment of the present invention.

[0022] Figure 6 This is the second structural schematic diagram of the cavity wall plate provided in an embodiment of the present invention.

[0023] Figure 7 It is a schematic diagram of the influence of different vacuum structures on the longitudinal flatness of the electric field obtained by simulating the finite element electromagnetic simulation software provided in an embodiment of the present invention.

[0024] Figure 8 It is a schematic structural diagram of the end face seal of a radio frequency quadrupole accelerator for multi-vacuum scenario applications provided by an embodiment of the present invention.

[0025] The reference numerals are as follows: 1. RF cavity; 11. first half cavity wall plate; 12. first middle wall plate; 13. second half cavity wall plate; 14. second middle wall plate; 15. grid hole; 16. first accommodating groove; 17. tuner port; 18. sampling port; 19. second sealing groove; 2. Wing plate; 3. End cap; 4. Connecting parts; 5. Vacuum cover plate; 51. Connecting flange. DETAILED DESCRIPTION

[0026] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0027] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and 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 devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0028] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0029] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0030] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0031] Combine the following Figure 2-Figure 8 The invention describes a radio frequency quadrupole accelerator for multi-vacuum scene applications according to an embodiment of the invention.

[0032] The embodiment of the present invention provides a radio frequency quadrupole field accelerator for multiple vacuum scene applications, such as Figures 2 to 6 As shown, the RF quadrupole accelerator for multi-vacuum scenario applications includes a RF cavity 1 and a vacuum cover 5; the cavity wall of the RF cavity 1 is provided with a grid hole 15 for vacuum extraction; the vacuum cover 5 is detachably installed at the position of the grid hole 15; when the vacuum cover 5 is installed at the position of the grid hole 15, it is used to maintain a vacuum environment in the RF cavity 1 in an independent vacuum usage scenario; when the vacuum cover 5 is removed from the position of the grid hole 15, it is used to place the RF cavity 1 in a vacuum chamber in an integrated vacuum usage scenario.

[0033] It is understandable that the cavity wall of the RF cavity 1 is provided with grid holes 15 for vacuuming to provide channels for vacuuming the RF cavity 1 , and the grid holes 15 serve as channels for gas migration during the vacuuming process of the RF cavity 1 .

[0034] It should be noted that in the prior art, Figure 1 As shown, a knife-edge flange is provided on the end face of the RF cavity 1, and the knife-edge flange has a lateral dimension. 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. In addition, the present invention disperses the existing concentrated larger extraction openings into smaller grid holes 15, which can reduce the influence of the vacuum structure on the RF performance (field uniformity and quality factor).

[0035] The radio frequency quadrupole field accelerator for multi-vacuum scenario application provided by an embodiment of the present invention provides a channel for evacuating the radio frequency cavity 1 by opening a grid hole 15 in the cavity wall of the radio frequency cavity 1. In an independent vacuum usage scenario, the vacuum cover is installed at the grid hole position to maintain a vacuum environment in the radio frequency cavity; in an integrated vacuum usage scenario, the vacuum cover is disassembled at the grid hole position to place the radio frequency cavity in a vacuum chamber for compact accelerator system integration; and the welded vacuum flange structure of the existing cavity wall of the radio frequency cavity 1 is eliminated, thereby effectively reducing the lateral size of the radio frequency cavity 1, thereby reducing the volume of the radio frequency cavity 1 to achieve a miniaturized design of the accelerator; in addition, the grid hole 15 can effectively reduce the influence of the vacuum channel structure on the radio frequency performance of the radio frequency cavity 1.

[0036] According to an embodiment of the present invention, a detachable vacuum cover plate 5 is provided at the position of the grid hole 15 of the RF cavity 1; the vacuum cover plate 5 is installed at the position of the grid hole 15 of the RF cavity 1 to achieve the sealing of the inner cavity of the RF cavity 1, and the vacuum cover plate 5 can also be removed and placed in a vacuum chamber for compact accelerator system integration. In this way, the RF quadrupole accelerator for multi-vacuum scene applications of this embodiment can be used in multiple scenes.

[0037] Optionally, the outer wall of the RF cavity 1 has a first accommodating groove 16 for accommodating the vacuum cover plate 5, the first side of the vacuum cover plate 5 has a vacuum groove connected to the grid hole 15, and the second side of the vacuum cover plate 5 has a connecting flange 51, which is connected to the vacuum groove.

[0038] It can be understood that a first receiving groove 16 is provided at the position of the grid hole 15 of the RF cavity 1, so as to achieve the blocking of 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, and when the vacuum cover plate 5 is installed in the first receiving groove 16, the vacuum groove of the vacuum cover plate 5 is connected to the grid hole 15, and a connecting flange 51 is provided on the second side of the vacuum cover plate 5, and the connecting flange 51 is connected to the vacuum groove; when the connecting flange 51 is connected to the vacuum pump, 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 detachable vacuum cover plate 5 is provided at the position of the grid hole 15 of the cavity wall, and the RF cavity 1 can generally increase 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 the evacuation of the RF cavity 1, so that it can be applied in multiple scenarios.

[0039] It is understandable that in the scenario of independent vacuum use of the RF cavity 1, vacuum blind plates and vacuum adapter flanges can be installed at the grid hole positions for installing molecular pumps or vacuum pipes; in the scenario of integrated vacuum use, after the vacuum blind plates or vacuum adapter 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 adapter flange is a structure with a connecting flange 51 integrated on the vacuum cover plate 5; the RF cavity 1 has a plurality of grid holes arranged circumferentially, and vacuum blind plates can be arranged in some of the grid holes, and vacuum adapter flanges can be arranged in some of the grid holes.

[0040] It should be noted that the miniaturization of the accelerator not only requires the miniaturization of the RF cavity 1, but also requires the simplification of its auxiliary equipment. In this embodiment, the cavity wall is provided with grid holes 15 for vacuuming, and after removing the vacuum cover 5, the RF cavity 1 can be placed in a vacuum chamber, which can effectively reduce the number and volume of vacuum auxiliary components.

[0041] It should be noted that the biggest contradiction and constraint factor in the design of the RF cavity 1 is the conflict between the reduction of the structural size and the layout of its RF structure (such as the mode separation structure) and the layout of the auxiliary structures (such as the vacuum extraction port and the sampling port 18). However, this embodiment places the RF cavity 1 in a vacuum chamber, which can largely solve or avoid these contradictions and constraints in the miniaturization of the RF cavity 1.

[0042] In an embodiment of the present invention, the lateral dimension (diameter) of the RF cavity 1 is less than 140 mm, which is reduced by ~20 mm compared with the existing RF cavity 1 structure (~160 mm) with the same resonant frequency and not optimized RFQ. At the same time, RF simulation and multi-physics field analysis show that the RF cavity 1 of the embodiment of the present invention does not affect the RF loss and quality factor of the cavity when applied in multiple scenarios. It should be noted here that the longitudinal inhomogeneity of the electromagnetic field can be adjusted by adjusting the structure of the RF cavity 1.

[0043] In one embodiment of the present invention, a first receiving groove 16 is opened at the position where the grid hole 15 is opened in the cavity wall, and screw holes located at the periphery of the grid hole 15 are arranged on the first receiving groove 16, and the vacuum cover plate 5 is arranged in the first receiving groove 16. Correspondingly, a connecting hole matching the threaded hole is arranged on the vacuum cover plate 5, and the vacuum cover plate 5 is arranged in the first receiving groove 16 of the cavity wall by bolts passing through the connecting hole and the threaded hole in sequence to block the grid hole 15; when the RF cavity 1 is placed in the vacuum chamber, the bolts and the vacuum cover plate 5 on the cavity wall are removed.

[0044] It is understandable that the cavity wall is provided with a first accommodating groove 16 , and the raw material of the RF cavity 1 corresponding to the first accommodating groove 16 , such as copper material, is omitted during the cavity wall processing, thereby reducing the raw material cost.

[0045] Furthermore, in order to improve the sealing performance of the vacuum cover plate 5 and the cavity wall, a sealing ring is provided between the vacuum cover plate 5 and the first receiving groove 16. In this embodiment, the sealing ring is a rubber ring, and a knife-edge flange does not need to be welded, thereby reducing the cavity volume.

[0046] In one embodiment of the present invention, the grid holes 15 include a plurality of long holes arranged side by side along the beam direction, and the long sides of the long holes are perpendicular to the beam direction.

[0047] It is understandable that the same cavity wall of the RF cavity 1 is provided with a plurality of long holes arranged side by side along the beam direction, and the plurality of long holes form a grid hole 15. It should be noted here that the number and size of the long holes can be reasonably designed according to the vacuum requirements of the RF cavity 1. For example, for the RF cavity 1 placed in the vacuum chamber, the number of long holes of the grid hole 15 can be appropriately increased. For the RF cavity 1 that does not need to be placed in the vacuum chamber, the number of long holes of the grid hole 15 is determined according to the effective extraction area.

[0048] For example, the RF cavity 1 is provided with 4 grid holes 15, which are arranged along the circumference of the RF cavity 1, and each grid hole 15 includes 11 long strip holes arranged along the beam direction (i.e., longitudinal direction), the long side direction of the long strip hole is perpendicular to the beam direction, the distance L1 between two adjacent long strip holes is 10 mm, and the length L2 of the long strip hole along the longitudinal direction is 5 mm; the two ends of the long strip hole along the long side direction are semicircular, and the length L3 of the straight section of the long strip hole between the two semicircular ends is 20 mm. It should be noted here that if there is interference with the process holes, the length of the long strip hole can be changed.

[0049] In one embodiment of the present invention, the RF cavity 1 includes a plurality of cavity wall plates connected end to end in sequence to form a cavity, the cavity wall plates are provided with grid holes 15 for vacuuming, and the inner wall of the cavity wall plates has a wing plate 2 extending toward the center of the RF cavity 1; the vacuum cover plate 5 is detachably arranged at the position of the grid hole 15 of the cavity wall plate.

[0050] It can be understood that the RF cavity 1 is surrounded by multiple cavity wall panels, and a wing plate 2 is connected to the inner wall of the cavity wall panel. The wing plate 2 and the cavity wall panel are processed as a whole to reduce the error caused by assembly welding between the wing plate 2 and the cavity wall panel.

[0051] It should be noted that in the prior art, the knife-edge flange is connected to the RF cavity 1 by welding, and the welding of the RF cavity 1 and the knife-edge flange is prone to deformation of the shape. However, the embodiment of the present invention provides a grid hole 15 in the cavity wall plate to provide a channel for vacuuming the cavity, thereby eliminating the existing vacuum flange structure and effectively reducing the volume of the RF cavity 1; and the wing plate 2 is integrally connected to the cavity wall plate, so that the wing plate 2 and the cavity wall plate are processed as an integral whole, which can reduce the error caused by the welding and assembly of the wing plate 2 and the cavity wall plate, thereby avoiding the defect that the RF performance of the RF cavity 1 is reduced due to the weld between the wing plate 2 and the cavity wall plate.

[0052] In one embodiment of the present invention, a higher operating frequency is adopted, and according to existing radio frequency power source products, it can be selected in the range of 650 MHz to 1 GHz.

[0053] The RF cavity 1 includes four cavity wall plates, and the RF cavity 1 is composed of four parts, specifically including a first half cavity wall plate 11, a first middle wall plate 12, a second half cavity wall plate 13 and a second middle wall plate 14 connected end to end in sequence, and grid holes 15 are opened on the first half cavity wall plate 11 and the second half cavity wall plate 13.

[0054] Each cavity wall plate is connected to a wing plate 2, and the number of wing plates 2 is the same as that of cavity wall plates. The RF cavity 1 has four wing plates 2, and the four wing plates 2 are respectively connected to the four cavity wall plates, and the wing plates 2 and the cavity wall plates are integrally formed. Specifically, the four wing plates 2 are respectively integrally connected to the first half cavity wall plate 11, the first middle wall plate 12, the second half cavity wall plate 13, and the second middle wall plate 14.

[0055] After the first half cavity wall plate 11, the first middle wall plate 12, the second half cavity wall plate 13 and the second middle wall plate 14 are connected end to end in sequence, the four wing plates 2 located in the cavity are evenly arranged along the same circumference with the center of the RF cavity 1 as the center; and the end of the wing plate 2 close to the center of the RF cavity 1 has an electrode, then the electrode centers of the four wing plates 2 are symmetrically arranged in the RF cavity 1.

[0056] For example, the electrode, the wing plate 2 and the cavity wall plate are processed as a whole, and the electrode, the wing plate 2 and the cavity wall plate are used as an integrally processed part.

[0057] Furthermore, the cross section of the RF cavity 1 is octagonal, the first half cavity wall plate 11 is recorded as the upper half cavity wall plate, the first middle wall plate 12 is recorded as the left middle wall plate, the second half cavity wall plate 13 is recorded as the lower half cavity wall plate, the second middle wall plate 14 is recorded as the right middle wall plate, the left middle wall plate is arranged 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 middle wall plate is arranged 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 here that up, down, left, and right are defined as the orientation when looking from the beam inlet of the RF cavity 1 to the beam outlet.

[0058] The upper cavity wall plate and the lower cavity wall plate each have three connected cavity walls, and the left middle wall plate and the right middle wall plate each have one cavity wall, so that the upper cavity wall plate, the left middle wall plate, the lower cavity wall plate, and the right middle wall plate are connected end to end in sequence to form a radio frequency cavity 1 with an octagonal cross-section, and the cavity wall located in the middle of the upper cavity wall plate and the lower cavity wall plate is connected with a wing plate 2, and grid holes 15 are arranged on the cavity walls on both sides of the upper cavity wall plate and the lower cavity wall plate.

[0059] Preferably, when the size of each cavity wall of the upper cavity wall plate and the lower cavity wall plate is consistent with the size of the cavity wall of the left middle wall plate and the right middle wall plate, the cross section of the radio frequency cavity 1 is a regular octagon.

[0060] According to the embodiment of the present invention, the grid holes 15 of all cavity walls are arranged in a central symmetric manner. The grid holes 15 are arranged in a periodic arrangement in the longitudinal direction, and the grid holes 15 on the four cavity walls at the same longitudinal position in the beam direction are arranged symmetrically. This arrangement scheme avoids the disturbance of the electric field in the central area of ​​the beam channel caused by the introduction of the grid holes 15, and ensures the uniformity of the electric field along the circumferential direction.

[0061] It should be noted that even if the grid holes 15 are introduced to cause a slight disturbance in the longitudinal distribution of the electric field in the central area of ​​the beam channel, it can be adjusted by fine-tuning the cavity RF structure and tuning after the RF cavity 1 is processed.

[0062] In one embodiment of the present invention, the first half cavity wall plate 11 has a tuner port 17 and a sampling port 18 .

[0063] For example, the first half cavity wall plate 11 has tuner ports 17 located on both sides of the grid hole 15 along the beam direction, and has a sampling port 18 located between one of the tuner ports 17 and the grid hole 15. Of course, the second half cavity wall plate 13 also has a tuner port 17 and a sampling port 18, so that the first half cavity wall plate 11 and the second half cavity wall plate 13 have the same structure.

[0064] Furthermore, threaded holes are provided at the periphery of the tuner port 17 of the first half-cavity wall plate 11 and the second half-cavity wall plate 13, so as to facilitate connecting the tuner at the tuner port 17 by bolts; and threaded holes are also provided at the periphery of the sampling port 18 of the first half-cavity wall plate 11 and the second half-cavity wall plate 13, so as to facilitate connecting the sampling ring at the sampling port 18 by bolts.

[0065] In one embodiment of the present invention, connecting components 4 are respectively provided at both ends of the RF cavity 1, the first end of the connecting component 4 is connected to the end of the RF cavity 1, and the second end of the connecting component 4 has a connecting piece, which is used to connect the RF cavity 1 with the end cover 3, and the connecting piece is also used to connect two RF cavities 1.

[0066] Optionally, the connecting component 4 can adopt a connecting jacket; specifically, the connecting component 4 includes a plurality of L-shaped connecting plates, the number of the L-shaped connecting plates is equal to the number of the cavity wall plates, and the positions correspond one to one, one side of the plurality of L-shaped connecting plates are respectively connected to the outer walls of the ends of the plurality of cavity wall plates, and the other side of the L-shaped connecting plate faces the side away from the center of the RF cavity 1, and the other side of the L-shaped connecting plate serves as a connector.

[0067] Furthermore, the connector has a connecting portion. For example, a threaded hole is provided on the other side of the L-shaped connecting plate as a 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, and the positioning portion can be a positioning hole or a positioning bump.

[0068] In this embodiment, the end cover 3 is connected to the end face of the first half cavity wall panel 11 and the end face of the second half cavity wall panel 13 by bolts, and a second sealing groove 19 is provided on the end face of the first half cavity wall panel 11 and the end face of the second half cavity wall panel 13, so that a sealing member is arranged in the second sealing groove 19 to improve the sealing performance of the connection between the end cover 3 and the RF cavity 1; and a connecting jacket is provided between the end face of the end cover 3 and the end face of the RF cavity 1.

[0069] It should be noted that a mounting groove is provided at the position of the tuner port 17 of the cavity wall plate to form a sealing plane. When the tuner is installed, the mounting groove forms a positioning groove for the tuner, and a sealing member can be provided in the mounting groove to improve the sealing of the tuner connection. Of course, a corresponding mounting groove is also provided at the position of the sampling port 18 of the cavity wall plate.

[0070] In a specific embodiment of the present invention, a radio frequency quadrupole field accelerator for multi-vacuum scene applications includes a radio frequency cavity 1 and a vacuum cover plate 5 .

[0071] The RF cavity 1 includes a first half cavity wall plate 11, a first middle wall plate 12, a second half cavity wall plate 13 and a second middle wall plate 14. The first half cavity wall plate 11 and the second half cavity wall plate 13 each have three connected cavity walls, the first middle wall plate 12 and the second middle wall plate 14 each have a cavity wall, and the first half cavity wall plate 11, the first middle wall plate 12, the second half cavity wall plate 13 and the second middle wall plate 14 are connected end to end in sequence to form a RF cavity 1 with a regular octagonal cross-section.

[0072] The RF cavity 1 also includes four wing panels 2. The cavity walls located in the middle of the first half cavity wall panel 11 and the second half cavity wall panel 13 are respectively connected to the wing panels 2. The first middle wall panel 12 and the second middle wall panel 14 are respectively connected to the wing panels 2. The wing panels 2 connected to the first half cavity wall panel 11 and the second half cavity wall panel 13 are arranged in a vertical direction. The first half cavity wall panel 11 and its upper wing panel 2 serve as the upper vertical wing, the second half cavity wall panel 13 and its upper wing panel 2 serve as the lower vertical wing, the first middle wall panel 12 and its upper wing panel 2 serve as the left horizontal wing, and the second middle wall panel 14 and its upper wing panel 2 serve as the right horizontal wing. The first half cavity wall panel 11 and its upper wing panel 2 are processed as an integral whole, and the second half cavity wall panel 13 and its upper wing panel 2 are processed as an integral whole, which can reduce the error caused by the assembly welding of the components. At the same time, the reduction of assembly welding can avoid the problem of the degradation of the RF performance of the RF cavity 1 caused by the weld. Of course, the first intermediate wall panel 12 and the wing panel 2 as well as the second intermediate wall panel 14 and the wing panel 2 can be processed in one piece.

[0073] 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 are provided with grid holes 15. The cavity wall provided with the grid holes 15 is inclined, and the cavity wall is recorded as an inclined surface. Then, the cavity walls (inclined surfaces) of the four quadrants of the RF cavity 1 are provided with grid holes 15 to provide a channel for evacuating the RF cavity 1. At the same time, after 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 area are ensured to meet the design requirements of beam dynamics.

[0074] A vacuum cover plate 5 is arranged at the position of the grid hole 15 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 field accelerator for multi-vacuum scenario application of this embodiment has the function of not being placed in a vacuum chamber, and installing a vacuum pump group for independent test operation like a traditional accelerator system. The vacuum cover plate 5 on the cavity wall plate can also be removed and placed in the vacuum chamber for integrated use of a compact accelerator system.

[0075] The welding surface is the junction of the straight edge and the beveled edge of the cavity wall close to the left horizontal wing and the right horizontal wing. The solder groove is located on the upper welding plane of the horizontal wing (left horizontal wing and right horizontal wing) and the welding plane of the lower vertical wing. The two vertical wings (upper vertical wing and lower vertical wing) are respectively processed as a whole in the CNC machining center, which reduces the error caused by the assembly of the octagonal wall panel (cavity wall panel) and the wing panel 2.

[0076] like Figure 1 and Figure 2As shown, the lateral dimensions of the RF cavity 1 of this embodiment are compared with those of the traditional RFQ RF cavity 1 structure. The lateral dimension B of the RF cavity 1 of this embodiment is 138.24 mm, which is 27% smaller than the lateral dimension A of the traditional structure of 190 mm, thereby reducing material usage and having considerable application prospects in the field of miniaturized applications.

[0077] The radio frequency quadrupole field accelerator for multi-vacuum scenario application provided by the embodiment of the present invention, the grid holes 15 opened on the cavity wall plate and the vacuum cover plate 5 detachably arranged at the position of the grid holes 15 of the cavity wall plate serve as a vacuum sealing structure, eliminating the existing vacuum brazing flange structure, reducing the volume of the auxiliary equipment, and at the same time eliminating the tuner inaccuracy caused by the knife-edge flange copper gasket, and avoiding the difficulty in assembling the flange bolts caused by the compact structure.

[0078] In the radio frequency quadrupole field accelerator for multi-vacuum scenario applications provided in an embodiment of the present invention, the grid holes 15 on the cavity wall plate provide a channel for the migration of gas molecules during vacuum extraction. Compared with the vacuum channel of the knife-edge flange, the grid holes 15 have a larger exhaust channel cross-sectional area, which is more conducive to achieving high vacuum or even ultra-high vacuum requirements inside the radio frequency cavity 1.

[0079] like Figure 7 As shown, curve a represents that no vacuum hole is opened in the cavity wall, curve b represents that a circular vacuum hole is opened in the cavity wall (the existing vacuum hole connected to the knife-edge flange), and curve c represents that the cavity wall of this embodiment has a grid hole 15. By comparing the longitudinal flatness of the electric field using different vacuum ports, it can be seen that the grid hole 15 structure of the embodiment of the present invention has almost no effect on the longitudinal flatness of the electric field, while the use of a circular vacuum hole has a great effect on the longitudinal flatness of the electric field, and exceeds the range required by the beam dynamics.

[0080] like Figure 8 As shown, the end of the RF cavity 1 of this embodiment is connected to the end cover 3, and a second sealing groove 19 is set 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 that a sealing member is arranged in the second sealing groove 19 to improve the sealing of the connection between the end cover 3 and the RF cavity 1; and a connecting jacket is set between the end cover 3 and the end face of the RF cavity 1. The end face sealing structure of the RF cavity 1 of this embodiment adopts a vacuum sealing groove. Compared with the knife-edge flange sealing structure, it integrates the CF200 stainless steel knife-edge flange, greatly reducing the structural volume and complexity of the RFQ RF cavity 1. At the same time, compared with the knife-edge flange structure, the rubber ring vacuum sealing groove structure eliminates the problem of installing a large number of bolts, and is more convenient to install.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions 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 scene applications, characterized in that: include: A radio frequency cavity (1), wherein a cavity wall of the radio frequency cavity (1) is provided with grid holes (15) for vacuuming; A vacuum cover plate (5) is detachably mounted at the position of the grid hole (15); when the vacuum cover plate (5) is mounted at the position of the grid hole (15), it is used to maintain a vacuum environment in the radio frequency cavity (1) in an independent vacuum usage scenario; when the vacuum cover plate (5) is detached from the position of the grid hole (15), it is used to place the radio frequency cavity (1) in a vacuum chamber in an integrated vacuum usage scenario.

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

3. The radio frequency quadrupole accelerator for multi-vacuum scene applications according to claim 1, characterized in that: The grid holes (15) comprise a plurality of long holes arranged side by side along the beam direction, wherein the long sides of the long holes are perpendicular to the beam direction.

4. The radio frequency quadrupole accelerator for multi-vacuum scene applications according to any one of claims 1 to 3, characterized in that: The radio frequency cavity (1) comprises a plurality of cavity wall plates connected end to end in sequence, and the inner walls of the cavity wall plates have wing plates (2) extending towards the center of the radio frequency cavity (1).

5. The radio frequency quadrupole accelerator for multi-vacuum scene applications according to claim 4, characterized in that: The plurality of cavity wall panels comprise a first half cavity wall panel (11), a first middle wall panel (12), a second half cavity wall panel (13) and a second middle wall panel (14) which are connected end to end in sequence; the grid holes (15) are arranged 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 plate (11), the wing plates (2) of the first middle wall plate (12), the wing plates (2) of the second half-cavity wall plate (13) and the wing plates (2) of the second middle wall plate (14) are evenly distributed in the circumferential direction.

6. The radio frequency quadrupole accelerator for multiple vacuum scene applications 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 located in the middle is connected to the wing plate (2), and the cavity walls located on both sides are provided with the grid holes (15).

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

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

9. The radio frequency quadrupole accelerator for multiple vacuum scene applications according to claim 4, characterized in that: It also comprises a connecting component (4), a first end of the connecting component (4) being connected to the end of the radio frequency cavity (1), and a second end of the connecting component (4) having a connecting piece.

10. The radio frequency quadrupole accelerator for multi-vacuum scene applications according to claim 9, characterized in that: The connecting piece comprises a connecting portion and a positioning portion.

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