Radio frequency linear accelerator and linear accelerator system

Abstract

The present application relates to a kind of radio frequency linear accelerator and linear accelerator system, radio frequency linear accelerator includes radio frequency acceleration cavity, longitudinal electrode group, transverse electrode group and assembly support, wherein, radio frequency acceleration cavity is provided with longitudinal acceleration section and transverse acceleration section along the direction of advance of incident particle beam.Longitudinal electrode group includes two longitudinal electrode plates, and longitudinal electrode group is longitudinally focused to particle beam.Transverse electrode group is correspondingly arranged in transverse acceleration section, and transverse electrode group includes two transverse electrode plates, and transverse electrode group is transversely focused to particle beam.Assembly support is structural mounting component, and longitudinal electrode group and transverse electrode group are all installed on assembly support.Accelerator whole is focused to particle beam in radio frequency acceleration cavity in longitudinal direction and transverse direction, it helps to improve the phase shift of horizontal direction and vertical direction in unit acceleration structure, can separate the electric focusing force of horizontal and vertical direction, make beam dynamics process simple and clear.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-frequency acceleration structure, in particular to a radio frequency linear accelerator and a linear accelerator system. BACKGROUND

[0002] Drift tube linear accelerator (DTL) is a commonly used linear accelerator type, and its key structure is a hollow cylinder with a specific gap length and a specific inner and outer diameter. The adjacent two hollow cylinders have a radio frequency electric field in the gap for accelerating protons or heavy ions. The transverse focusing effect of the acceleration electric field generated by this structure is too small to be ignored. The commonly used cylindrical drift tube structure cannot distinguish the horizontal and vertical electric focusing forces, which causes the coupling of horizontal and vertical beam dynamics, and is not conducive to the improvement of beam dynamics quality. SUMMARY

[0003] In view of the above technical problems, the present application provides a radio frequency linear accelerator and a linear accelerator system, which fundamentally breaks through the basic structure of the existing cylindrical drift tube, can separate the horizontal and vertical electric focusing forces, and makes the beam dynamics process simple and clear.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0005] A radio frequency linear accelerator, comprising:

[0006] A radio frequency acceleration cavity, which is provided with a longitudinal acceleration section and a transverse acceleration section in the advancing direction of the incident particle beam;

[0007] A longitudinal electrode group, which is correspondingly arranged in the longitudinal acceleration section, and comprises two longitudinal electrode plates arranged on both sides of the particle beam advancing direction, and the longitudinal electrode group performs longitudinal focusing on the particle beam;

[0008] A transverse electrode group, which is correspondingly arranged in the transverse acceleration section, and comprises two transverse electrode plates arranged on both sides of the particle beam advancing direction, and the transverse electrode group performs transverse focusing on the particle beam;

[0009] An assembly support, wherein the longitudinal electrode group and the transverse electrode group are mounted on the assembly support.

[0010] In one embodiment, the longitudinal acceleration section and the transverse acceleration section are each provided with a plurality of sections, and the longitudinal acceleration sections and the transverse acceleration sections are distributed in a spaced manner.

[0011] In one of the embodiments, the longitudinal electrode plates are uniformly spaced from the transverse electrode plates.

[0012] In one of the embodiments, the assembly support includes a crossbeam and support rods.

[0013] The crossbeam is uniformly distributed with four rods along the circumference of the RF accelerating cavity.

[0014] The number and position of the support rods correspond to the longitudinal electrode plates and the transverse electrode plates, one end of the support rods is connected with the crossbeam, and the other end extends to the axial direction of the RF accelerating cavity and is connected with the longitudinal electrode plates or the transverse electrode plates.

[0015] In one of the embodiments, the support rods are detachably connected with the crossbeam.

[0016] In one of the embodiments, the support rods are threadedly connected with the crossbeam.

[0017] In one of the embodiments, the RF accelerating cavity is further provided with a combined accelerating section along the advancing direction of the incident particle beam.

[0018] The combined accelerating section is correspondingly provided with a combined electrode group, which includes two oppositely arranged first electrodes and two oppositely arranged second electrodes, the first electrodes and the second electrodes are vertically arranged; the combined electrode group is installed on the assembly support.

[0019] The combined electrode group longitudinally and transversely focuses the particle beam.

[0020] In one of the embodiments, the combined accelerating section is arranged in the middle part of the longitudinal accelerating section and the transverse accelerating section.

[0021] In one of the embodiments, the longitudinal accelerating section, the combined accelerating section and the transverse accelerating section are sequentially arranged to form a focusing period.

[0022] The RF accelerating cavity is provided with a plurality of the focusing periods along the advancing direction of the incident particle beam.

[0023] The application further provides a linear accelerator system, which includes the RF linear accelerator described in the above scheme.

[0024] The application has the following advantages due to the above technical scheme:

[0025] The accelerator as a whole will focus the particle beam in the radio frequency accelerating cavity in the longitudinal direction and the transverse direction through the longitudinal accelerating section and the transverse accelerating section, wherein, due to the split arrangement of the longitudinal electrode group and the transverse electrode group, the horizontal and vertical electric focusing functions are separated by using the structure of the application, that is, only one of the horizontal electric focusing force or the vertical electric focusing force exists in a single accelerating unit, and they cannot exist simultaneously, weakening the coupling effect of the beam in two directions, which helps to improve the phase shift in the horizontal direction and the vertical direction in the unit accelerating structure, fundamentally breaks through the basic structure of the existing cylindrical drift tube, can separate the horizontal and vertical electric focusing forces, and makes the beam dynamics process simple and clear. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a specific structure schematic diagram of the radio frequency linear accelerator in an embodiment of the application;

[0027] Figure 2 is Figure 1 is an enlarged view of A in FIG. 1;

[0028] Figure 3 is a specific structure schematic diagram of the assembly support in an embodiment of the application;

[0029] Figure 4 is a specific structure schematic diagram of the combined electrode group in an embodiment of the application;

[0030] The various marks in the drawings are as follows:

[0031] 1, radio frequency accelerating cavity;

[0032] 2, longitudinal electrode group; 21, longitudinal electrode plate;

[0033] 3, transverse electrode group; 31, transverse electrode plate;

[0034] 4, assembly support; 41, crossbeam; 42, support rod;

[0035] 5, combined electrode group; 51, first electrode; 52, second electrode. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the present application more clear, the technical scheme in the present application will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0037] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," "third," "fourth," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0038] Drift tube linear accelerators are a commonly used type of linear accelerator. The conventional cylindrical drift tube structure cannot distinguish between the horizontal and vertical focusing forces, causing coupling between the horizontal and vertical beam dynamics, which is detrimental to improving beam dynamics quality. To address these technical problems, this invention provides a radio frequency linear accelerator and linear accelerator system that fundamentally breaks through the basic structure of existing cylindrical drift tubes, enabling the separation of horizontal and vertical focusing forces and making the beam dynamics process simple and clear.

[0039] The technical solution of the present invention will be described in detail below with reference to specific examples.

[0040] Reference Figure 1 , Figure 2 as well as Figure 3 As shown, the present invention relates to a radio frequency linear accelerator, comprising a radio frequency accelerating cavity 1, a longitudinal electrode group 2, a transverse electrode group 3, and an assembly bracket 4. The radio frequency accelerating cavity 1 is provided with a longitudinal accelerating section and a transverse accelerating section along the direction of the incident particle beam. The longitudinal electrode group 2 is correspondingly disposed within the longitudinal accelerating section and includes two longitudinal electrode plates 21, which are arranged opposite each other on both sides of the particle beam's direction of travel, thus focusing the particle beam longitudinally. The transverse electrode group 3 is correspondingly disposed within the transverse accelerating section and includes two transverse electrode plates 31, which are arranged opposite each other on both sides of the particle beam's direction of travel, thus focusing the particle beam laterally. The assembly bracket 4 is a structural mounting component, on which both the longitudinal electrode group 2 and the transverse electrode group 3 are mounted.

[0041] Exemplarily, the accelerator as a whole will focus the particle beam in the radio frequency accelerating cavity 1 in the longitudinal direction and in the transverse direction through the longitudinal accelerating sections and the transverse accelerating sections, wherein, due to the split arrangement of the longitudinal electrode groups 2 and the transverse electrode groups 3, the horizontal and vertical electric focusing functions are separated by using the structure of the present application, that is, only one of the horizontal electric focusing force or the vertical electric focusing force exists in a single accelerating unit, and they do not exist simultaneously, weakening the coupling effect of the beam in the two directions, which helps to improve the phase shift in the horizontal direction and the vertical direction in the unit accelerating structure, fundamentally breaking through the basic structure of the existing cylindrical drift tube, separating the horizontal and vertical electric focusing forces, and making the beam dynamics process simple and clear.

[0042] Referring to Figure 2 and Figure 3 In an embodiment, specifically, a plurality of longitudinal accelerating sections and a plurality of transverse accelerating sections are provided, and the longitudinal accelerating sections and the transverse accelerating sections are distributed in a spaced manner, and the longitudinal accelerating sections and the transverse accelerating sections are distributed along the length direction of the radio frequency accelerating cavity 1 as a whole. After the particle beam enters the radio frequency accelerating cavity 1, the particle beam is focused by the longitudinally and transversely alternating accelerating sections arranged in a spaced manner. Specifically, the longitudinally and transversely alternating accelerating sections are distributed in a spaced alternating manner.

[0043] In this embodiment, in order to optimize the working stability of the accelerator, the longitudinal electrode plates 21 are perpendicular to the transverse electrode plates 31.

[0044] In an embodiment, the assembly support 4 is further refined. The assembly support 4 includes crossbeams 41 and support rods 42. The crossbeams 41 are evenly distributed around the radio frequency accelerating cavity 1, and each crossbeam 41 is provided with a support rod 42. The support rods 42 are mainly used for mounting the longitudinal electrode plates 21 and the transverse electrode plates 31. Therefore, the number and position of the support rods 42 correspond to the longitudinal electrode plates 21 and the transverse electrode plates 31. It should be noted that one end of each support rod 42 is connected to the crossbeam 41, and the other end extends towards the axial direction of the radio frequency accelerating cavity 1 and is connected to the longitudinal electrode plate 21 or the transverse electrode plate 31.

[0045] More preferably, in this embodiment, the support rods 42 and the crossbeams 41 are detachably connected. The detachable connection allows the support rods 42 to have a replaceable function.

[0046] During use of the accelerator, the electric focusing strength of the corresponding accelerating section can be flexibly adjusted by adjusting the distance between the facing electrode plates, thereby expanding the parameter selection range in the beam dynamics design. In this embodiment, the distance between the corresponding electrode plates can be adjusted by replacing support rods 42 of different lengths. Exemplarily, the transverse electric focusing strength of the electrode region can be significantly changed by adjusting the transverse distance of the transverse electrode plates 31, and the distance is inversely proportional to the electric focusing strength.

[0047] More preferably, in this embodiment, the support rods 42 are threadedly connected with the cross beams 41. It should be noted that the threaded connection allows the length of the support rods 42 to be finely adjusted by rotation, and this connection can further optimize the adjustable performance of the accelerator. By rotating the support rods 42, the spacing between the electrode plates can be adjusted according to the actual situation to optimize the distribution, so that the accelerator can achieve the optimal operating state.

[0048] Illustratively, in a cross-finger type high-frequency resonant cavity in a transverse electric mode, if a commonly used cylindrical drift tube is used, each drift tube needs to be connected with two support rods 42, and any error in any one support rod 42 will cause the drift tube to be difficult to install with the other corresponding support rod 42. With the structure of the present application, each support rod 42 only needs to be connected with one flat plate electrode, and the two support rods 42 are independent of each other, and the error of the support rod 42 can be corrected through the installation process of the flat plate electrode.

[0049] The present application also provides a linear accelerator system, which comprises the radio frequency linear accelerator mentioned in the above scheme.

[0050] Illustratively, the accelerator in the system will focus the particle beam in the radio frequency accelerating cavity 1 in the longitudinal direction and the transverse direction through the longitudinal acceleration section and the transverse acceleration section. Since the longitudinal electrode group 2 and the transverse electrode group 3 are separately arranged, the horizontal and vertical electric focusing functions can be separated by using the structure of the present application, that is, only one of the horizontal electric focusing force or the vertical electric focusing force exists in a single acceleration unit, and both do not exist at the same time, which weakens the coupling effect of the beam in the two directions, helps to improve the phase shift in the horizontal direction and the vertical direction in the unit acceleration structure, fundamentally breaks through the basic structure of the existing cylindrical drift tube, separates the horizontal and vertical electric focusing forces, and makes the beam dynamics process simple and clear.

[0051] Referring to Figure 4 As shown in the figure, in an embodiment, a combined acceleration section is further arranged in the radio frequency accelerating cavity 1 along the advancing direction of the incident particle beam. The combined acceleration section is provided with a combined electrode group 5, which comprises two oppositely arranged first electrodes 51 and two oppositely arranged second electrodes 52, and the first electrodes 51 and the second electrodes 52 are arranged perpendicularly. The combined electrode group 5 is installed on the assembly support 4, and the combined electrode group 5 focuses the particle beam in the longitudinal direction and the transverse direction. Specifically, in this embodiment, the combined acceleration section is arranged in the middle part of the longitudinal acceleration section and the transverse acceleration section.

[0052] In some extended embodiments, the longitudinal acceleration section, one or more combined acceleration sections, the transverse acceleration section and one or more combined acceleration sections are sequentially arranged to form a focusing period, which can enable the incident particles to continuously experience longitudinal focusing and then transverse focusing in the region, and thus the phase shift of the incident particles in the longitudinal and transverse directions can be further increased, and the tolerance of the acceleration structure to the divergence of the incident ion beam can be improved. The radio frequency acceleration cavity 1 is provided with a plurality of focusing periods in the advancing direction of the incident particle beam, and the transverse and longitudinal envelopes of the ion beam are controlled to be always within the range of the acceleration channel while the beam is accelerated. Compared with the radio frequency acceleration cavity with the conventional cylindrical drift tube structure, the radio frequency acceleration cavity with the embodiment can accommodate more acceleration units, and thus the incident particle beam can be accelerated to a higher energy.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A radio frequency linear accelerator, characterized in that, include: A radio frequency accelerating cavity, wherein the radio frequency accelerating cavity is provided with a longitudinal accelerating section and a transverse accelerating section along the direction of travel of the incident particle beam; A longitudinal electrode group is disposed within the longitudinal acceleration section. The longitudinal electrode group includes two longitudinal electrode plates, which are disposed opposite each other on both sides of the particle beam's forward direction. The longitudinal electrode group focuses the particle beam longitudinally. A transverse electrode group is disposed within the transverse acceleration section. The transverse electrode group includes two transverse electrode plates, which are disposed opposite each other on both sides of the particle beam's forward direction. The transverse electrode group performs transverse focusing on the particle beam. An assembly bracket is provided, on which both the longitudinal electrode group and the transverse electrode group are mounted; the assembly bracket includes a crossbeam and a support rod. Four beams are evenly distributed along the circumference of the radio frequency accelerating cavity. The number and position of the support rods are respectively set to correspond to the longitudinal electrode plate and the transverse electrode plate. One end of each support rod is connected to the crossbeam, and the other end extends towards the axis of the radio frequency acceleration cavity and is connected to the longitudinal electrode plate or the transverse electrode plate.

2. The radio frequency linear accelerator according to claim 1, characterized in that, There are several longitudinal acceleration sections and several transverse acceleration sections, and the longitudinal acceleration sections and the transverse acceleration sections are distributed at intervals.

3. The radio frequency linear accelerator according to claim 1 or 2, characterized in that, The longitudinal electrode plates and the transverse electrode plates are evenly distributed at intervals.

4. The radio frequency linear accelerator according to claim 1 or 2, characterized in that, The support rod is detachably connected to the crossbeam.

5. The radio frequency linear accelerator according to claim 4, characterized in that, The support rod is threadedly connected to the crossbeam.

6. The radio frequency linear accelerator according to claim 1, characterized in that, The radio frequency accelerating cavity is also provided with a combined accelerating section along the direction of the incident particle beam. A combined electrode group is correspondingly provided within the combined acceleration section. The combined electrode group includes two opposing first electrodes and two opposing second electrodes, with the first electrodes and second electrodes being arranged perpendicularly. The combined electrode group is mounted on the assembly bracket. The combined electrode assembly focuses the particle beam both longitudinally and laterally.

7. The radio frequency linear accelerator according to claim 6, characterized in that, The combined acceleration section is located at the middle of the longitudinal acceleration section and the lateral acceleration section.

8. The radio frequency linear accelerator according to claim 7, characterized in that, The longitudinal acceleration segment, the combined acceleration segment, and the lateral acceleration segment arranged in sequence combine to form a focusing cycle; The radio frequency accelerating cavity is provided with a number of focusing cycles along the direction of the incident particle beam.

9. A linear accelerator system, characterized in that, Includes the radio frequency linear accelerator according to any one of claims 1-8.

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