Compact type multidirectional symmetrical de-dispersive beam transmission system

Abstract

The utility model discloses a compact multi-directional symmetric achromatic beam transmission system, which belongs to the field of radiotherapy and solves the problem that the existing proton beam transmission line is not compact and flexible enough in layout. According to the utility model, an initial deflection secondary magnet, a four-stage magnet A, a four-stage magnet B, a four-stage magnet C, a deflection secondary magnet A, a four-stage magnet D, a four-stage magnet E and a deflection secondary magnet B are sequentially arranged along a proton beam direction; the initial deflection second-stage magnet, the fourth-stage magnet A, the fourth-stage magnet B, the fourth-stage magnet C and the deflection second-stage magnet A are arranged in an axial symmetry manner to form a symmetric achromatic structure; the initial deflection second-stage magnet, the fourth-stage magnet A, the fourth-stage magnet B, the fourth-stage magnet D, the fourth-stage magnet E and the deflection second-stage magnet B are arranged in a central symmetry mode to form an antisymmetric achromatic structure. According to the utility model, the beam dispersion is eliminated while the beam is deflected to the auxiliary transmission section, so that the deflected beam can meet the requirements of a treatment terminal without passing through the dispersion eliminating structure again.

Description

Technical Field

[0001] This utility model belongs to the field of radiotherapy, specifically relating to a compact multi-directional symmetrical achromatic beam transmission system. Background Technology

[0002] Proton therapy systems use proton beams to irradiate tumor lesions. After being accelerated by an accelerator, protons are modulated in an energy selection system and then transported to the treatment terminal by a beam transport system before entering the body. Initially, the proton beams release very limited energy, but upon reaching a specific depth, they release a large amount of energy instantaneously, forming a "Bragg peak" energy release trajectory. Utilizing this characteristic, proton beams can deliver high-dose irradiation to tumor lesions while avoiding normal human tissue, maximizing therapeutic efficacy while minimizing side effects. Currently, my country's advanced proton medical devices are still mainly imported, and there is a significant gap between China's key proton therapy technologies and international standards. Given the technological shortcomings of my country's high-end radiotherapy equipment and the increasing number of cancer patients, research into key proton therapy technologies is urgently needed.

[0003] Addressing the practical needs of large, medium, and small hospitals and research institutions in my country for building proton therapy centers, this project aims to achieve flexible deployment of multiple treatment terminals within limited space, while minimizing the number of transmission line components to reduce system costs. A compact, flexible proton therapy beam transmission system with reduced transmission line components is one of the urgent needs for the widespread construction of proton therapy centers in medical and research institutions in the future.

[0004] Dispersion is a crucial parameter in beam transmission, reflecting the relationship between the momentum dispersion of the beam and the size of the beam envelope. Eliminating dispersion decouples the momentum dispersion from the transverse envelope, which is beneficial for beam transmission and allows for better matching with the beam requirements of the treatment terminal. Therefore, appropriate structures need to be incorporated into the beam transmission line of a proton therapy system to eliminate dispersion and ensure that the dispersion function of the beam at the treatment terminal is zero.

[0005] Traditional multi-terminal proton therapy systems typically use a long, straight beam transmission section with zero dispersion function as the main beam transmission line, from which the beams from each treatment terminal are drawn. Dispersion is introduced during beam deflection at each treatment terminal, necessitating additional anti-dispersion structures. The long, straight beam transmission section significantly limits the flexibility of beam transmission line placement; additional magnetic components also increase the cost of the proton therapy facility.

[0006] How to arrange multi-terminal beam transmission lines under limited and complex building conditions to form a construction plan for a compact and multi-purpose proton therapy system that meets the cost expectations and clinical research needs of various institutions is one of the important directions for the current research and development of key technologies for proton therapy. Utility Model Content

[0007] The purpose of this invention is to provide a compact, multi-directional, symmetrical, achromatic beam transmission system to solve the problems of insufficient compactness and flexibility, and high cost of existing proton beam transmission line layouts.

[0008] The technical solution of this utility model is: a compact multi-directional symmetrical achromatic beam transmission system, wherein an initial deflecting secondary magnet, a quaternary magnet A, a quaternary magnet B, a quaternary magnet C, a deflecting secondary magnet A, a quaternary magnet D, a quaternary magnet E and a deflecting secondary magnet B are arranged sequentially along the proton beam direction;

[0009] The initial deflecting secondary magnet, quaternary magnet A, quaternary magnet B, quaternary magnet C, and deflecting secondary magnet A are arranged axially symmetrically to form a symmetrical achromatic structure;

[0010] The initial deflection secondary magnet, quaternary magnet A, quaternary magnet B, quaternary magnet D, quaternary magnet E, and deflection secondary magnet B are arranged in a centrally symmetrical manner, forming an antisymmetric achromatic structure.

[0011] As a further improvement of this utility model, one or more symmetrical achromatic extension units and one or more antisymmetric achromatic extension units are provided at the rear end of the deflecting secondary magnet B.

[0012] The symmetrical achromatic extension unit is provided with a quadrupole magnet F, a quadrupole magnet G and a deflecting secondary magnet C in sequence along the proton beam direction. The initial deflecting secondary magnet, quadrupole magnet A, quadrupole magnet B, quadrupole magnet F, quadrupole magnet G and deflecting secondary magnet C are arranged in an axially symmetrical manner.

[0013] The antisymmetric achromatic extension unit is provided with a quadrupole magnet H, a quadrupole magnet I and a deflecting secondary magnet D in sequence along the proton beam direction. The initial deflecting secondary magnet, quadrupole magnet A, quadrupole magnet B, quadrupole magnet H, quadrupole magnet I and deflecting secondary magnet D are arranged in a centrally symmetrical manner.

[0014] As a further improvement of this utility model, the deflecting secondary magnet A, deflecting secondary magnet B, deflecting secondary magnet C, and deflecting secondary magnet D are respectively connected to the fixed experimental beam treatment terminal.

[0015] As a further improvement of this utility model, the fixed experimental beam therapy terminal is provided with two terminal first quadrupole magnets, a vacuum chamber, two terminal second quadrupole magnets, an X-scanning magnet, a Y-scanning magnet, a beam measurement system, and a center point arranged sequentially along the proton beam direction.

[0016] Compared with the traditional beam transmission line design of multi-terminal proton therapy systems, this invention has the following advantages:

[0017] 1. Unlike traditional layouts that use a long, straight main beam transmission section and employ an achromatic structure to eliminate the dispersion function introduced by deflecting the beam to the secondary transmission section, this invention eliminates beam dispersion using a symmetrical or anti-symmetrical structure while deflecting the beam to the secondary transmission section (treatment terminal). This allows the deflected beam to meet the requirements of the treatment terminal without needing to pass through an achromatic structure again. This technical solution reduces the additional space occupation and equipment required for each treatment terminal to have its own achromatic structure in the traditional layout, effectively reducing the construction cost of the proton therapy system and improving the flexibility of the layout.

[0018] 2. The symmetrical achromatic extension unit and the antisymmetric achromatic extension unit in this utility model can be arbitrarily superimposed according to the actual building layout and the number of treatment terminals required, which can form a beam transmission line layout with multiple deflection directions and multiple branches. This is conducive to the flexible arrangement of beam transmission lines in large, medium and small hospitals and research institutions, and realizes the construction of multi-terminal and multi-purpose proton therapy systems under the conditions of complex building space and limited budget. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the first embodiment of this utility model;

[0020] Figure 2 This is a schematic diagram illustrating the introduction of a dispersion function in the first embodiment of this utility model;

[0021] Figure 3 This is the dispersion function diagram of the first embodiment of this utility model;

[0022] Figure 4 This is a structural schematic diagram of the second embodiment of this utility model.

[0023] In the diagram: 101 - Initial deflection secondary magnet; 102 - Quaternary magnet A; 103 - Quaternary magnet B; 104 - Quaternary magnet C; 105 - Deflection secondary magnet A; 106 - Quaternary magnet D; 107 - Quaternary magnet E; 108 - Deflection secondary magnet B; 200 - Symmetrical achromatic extension unit; 201 - Quaternary magnet F, 202 - Quaternary magnet G; 203 - Deflection secondary magnet C; 300 - Antisymmetric achromatic extension unit; 301 - Quaternary magnet H; 302 - Quaternary magnet I; 303 - Deflection secondary magnet D; 400 - Fixed experimental beam treatment terminal; 401 - Terminal first quadrupole magnet; 403 - Vacuum chamber; 404 - Terminal second quadrupole magnet; 406 - X-scanning magnet; 407 - Y-scanning magnet; 408 - Beam measurement system; 409 - Center point. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1

[0026] like Figure 1 As shown, a compact multidirectional symmetrical achromatic beam transmission system comprises, along the proton beam direction, an initial deflecting secondary magnet 101, a quaternary magnet A 102, a quaternary magnet B 103, a quaternary magnet C 104, a deflecting secondary magnet A 105, a quaternary magnet D 106, a quaternary magnet E 107, and a deflecting secondary magnet B 108. The initial deflecting secondary magnet 101, quaternary magnet A 102, quaternary magnet B 103, quaternary magnet C 104, and deflecting secondary magnet A 105 are arranged axially symmetrically to form a symmetrical achromatic structure; the initial deflecting secondary magnet 101, quaternary magnet A 102, quaternary magnet B 103, quaternary magnet D 106, quaternary magnet E 107, and deflecting secondary magnet B 108 are arranged centrally symmetrically to form an antisymmetric achromatic structure.

[0027] By arranging deflecting diodes and quadrupoles with axial symmetry (symmetric achromatic structure) or centrosymmetry (antisymmetric achromatic structure), beam deflection can be achieved even when the beam dispersion is zero after deflection. During beam deflection, the same magnitude of current must be supplied to the symmetrically positioned deflecting diodes to generate a symmetrical deflecting magnetic field, and the same magnitude of current must be supplied to the symmetrically positioned quadrupoles to generate a symmetrical focusing magnetic field. Specifically:

[0028] When the symmetrical de-dispersion structure deflects the beam, the same current should be supplied to the initial deflecting secondary magnet 101 and the deflecting secondary magnet A105 to generate a symmetrical deflection magnetic field, and the same current should be supplied to the quaternary magnet A102 and the quaternary magnet C104 to generate a symmetrical focusing magnetic field. The current supplied to the above magnets should ensure that the superimposed magnetic field generated can limit the smooth transmission of the beam in the pipe and achieve the function of eliminating dispersion.

[0029] When the anti-symmetric achromatic structure deflects the beam, the quadrupole magnet C 104 and the deflecting secondary magnet A 105 are not in operation. The same current needs to be supplied to the initial deflecting secondary magnet 101 and the deflecting secondary magnet B 108 to generate a symmetrical deflecting magnetic field. The same current needs to be supplied to the quadrupole magnet A 102 and the quadrupole magnet 107 to generate a symmetrical focusing magnetic field. At the same time, the same current needs to be supplied to the quadrupole magnet B 103 and the quadrupole magnet D 106 to generate a symmetrical focusing magnetic field. The current supplied to the above magnets should ensure that the superimposed magnetic field generated can limit the smooth transmission of the beam in the pipe and achieve the function of eliminating dispersion.

[0030] This embodiment provides two fixed-beam treatment chambers, with deflecting secondary magnets A 105 and B 108 respectively connected to a fixed experimental beam treatment terminal 400. The fixed experimental beam treatment terminal 400, along the proton beam direction, is sequentially equipped with two terminal first quadrupole magnets 401, a vacuum chamber 403, two terminal second quadrupole magnets 404, an X-scanning magnet 406, a Y-scanning magnet 407, a beam measurement system 408, and an isocenter point 409. The terminal first quadrupole magnet 401 is used to control the beam envelope of the deflected beam; the vacuum chamber assembly 403 is used for evacuation and is equipped with a fluorescent target and a Faraday cylinder, which are used to monitor the beam status during the operation of the entire proton beam system and to block the proton beam when the entire proton beam system needs to be stopped, blocking the beam in front of the treatment chamber; the terminal second quadrupole magnet 404 is used to control the beam so that it converges into a beam spot of the required size at the isocenter point; the X-scanning magnet 406, the Y-scanning magnet 407, and the beam measurement system 408 constitute the core components of the fixed experimental beam treatment head, which can realize an active point scanning irradiation field of not less than 30cm×40cm and deliver the proton beam to the isocenter point 409.

[0031] Symmetrical achromatic structures and antisymmetric achromatic structures employ the principles of symmetric achromatic structure and antisymmetric achromatic structure, respectively, to achieve beam deflection and transmission under dispersion-eliminating conditions within a limited building layout.

[0032] In this embodiment, a dispersion function is introduced when the main beam is deflected (point 1), and eliminated when entering the secondary transmission segment of branch 1 (point 2) and branch 2 (point 4). The dispersion function is zero at the treatment terminal of branch 1 (point 3) and the treatment terminal of branch 2 (point 5). Figure 2 , Figure 3 As shown. Here, the secondary transmission section connected to the deflecting secondary magnet A 105 is branch 1, and the secondary transmission section connected to the deflecting secondary magnet B 108 is branch 2.

[0033] Example 2

[0034] like Figure 4As shown, the difference between this embodiment and Embodiment 1 is that: a symmetrical achromatic extension unit 200 and an antisymmetric achromatic extension unit 300 are further provided at the rear end of the deflecting secondary magnet B 108; the symmetrical achromatic extension unit 200 is arranged with a quadrupole magnet F 201, a quadrupole magnet G 202 and a deflecting secondary magnet C 203 in sequence along the proton beam direction, and the initial deflecting secondary magnet 101, quadrupole magnet A 102, quadrupole magnet B 103, quadrupole magnet F 201, quadrupole magnet G 202 and deflecting secondary magnet C 203 are arranged axially symmetrically; the antisymmetric achromatic extension unit 300 is arranged with a quadrupole magnet H 301, a quadrupole magnet I 302 and a deflecting secondary magnet D 303 in sequence along the proton beam direction, and the initial deflecting secondary magnet 101, quadrupole magnet A 102, quadrupole magnet B 103, quadrupole magnet H 301 and quadrupole magnet I 303 are arranged axially symmetrically; 302 and deflecting secondary magnet D 303 are arranged in a centrally symmetrical manner. Deflecting secondary magnet C 203 and deflecting secondary magnet D 303 are respectively connected to the fixed experimental beam treatment terminal 400. This embodiment can provide four fixed beam treatment chambers.

[0035] The initial deflection secondary magnet 101, quaternary magnet A 102, quaternary magnet B 103, quaternary magnet D 106, quaternary magnet E 107, quaternary magnet F 201, quaternary magnet G 202 and deflection secondary magnet C 203 constitute a symmetrical achromatic extension structure.

[0036] The initial deflection secondary magnet 101, quaternary magnet A 102, quaternary magnet B 103, quaternary magnet D 106, quaternary magnet E 107, quaternary magnet F 201, quaternary magnet G 202, quaternary magnet H 301, quaternary magnet I 302 and deflection secondary magnet D 303 constitute an antisymmetric achromatic extension structure.

[0037] Similarly, when operating the deflection beam, the same magnitude of current must be supplied to the deflection secondary magnets at symmetrical positions in the structure to generate a symmetrical deflection magnetic field, and the same magnitude of current must be supplied to the quaternary magnets at symmetrical positions in the structure to generate a symmetrical focusing magnetic field. Specifically:

[0038] When the symmetrical dedispersion structure deflects the beam, the same current must be supplied to the initial deflecting secondary magnet 101 and the deflecting secondary magnet A105 to generate a symmetrical deflection magnetic field, and the same current must be supplied to the quaternary magnet A102 and the quaternary magnet C104 to generate a symmetrical focusing magnetic field. The current supplied to the above magnets should ensure that the magnetic field they generate can ensure that the beam is transmitted smoothly in the pipe and can realize the function of eliminating dispersion of the symmetrical dedispersion structure.

[0039] When the anti-symmetric dedispersion structure deflects the beam, the quadrupole magnet C 104 and the deflecting secondary magnet A 105 are not working. The same current needs to be supplied to the initial deflecting secondary magnet 101 and the deflecting secondary magnet B 108 to generate a symmetrical deflection magnetic field. The same current needs to be supplied to the quadrupole magnet A 102 and the quadrupole magnet E 107 to generate a symmetrical focusing magnetic field. At the same time, the same current needs to be supplied to the quadrupole magnet B 103 and the quadrupole magnet D 106 to generate a symmetrical focusing magnetic field. The current supplied to the above magnets should ensure that the magnetic field they generate can ensure that the beam is transmitted smoothly in the pipe and can realize the function of eliminating dispersion of the symmetrical dedispersion structure.

[0040] When the symmetrical achromatic extension structure deflects the beam, the quadrupole magnet C104, the deflecting secondary magnet A105, and the deflecting secondary magnet B108 are not in operation. A symmetrical deflecting magnetic field needs to be generated by supplying the same current to the initial deflecting secondary magnet 101 and the deflecting secondary magnet C203, a symmetrical focusing magnetic field needs to be generated by supplying the same current to the quadrupole magnet A102 and the quadrupole magnet G202, a symmetrical focusing magnetic field needs to be generated by supplying the same current to the quadrupole magnet B103 and the quadrupole magnet F201, and a symmetrical focusing magnetic field needs to be generated by supplying the same current to the quadrupole magnet D106 and the quadrupole magnet E107. The current supplied to these magnets should ensure that the superimposed magnetic field generated can restrict the beam's smooth transmission in the pipe and achieve the function of eliminating dispersion.

[0041] When the anti-asymmetric achromatic extension structure deflects the beam, the quadrupole magnet C104, deflecting secondary magnets A105, B108, and C203 are not in operation. A symmetrical deflecting magnetic field needs to be generated by supplying the same current to the initial deflecting secondary magnet 101 and the deflecting secondary magnet D303; a symmetrical focusing magnetic field needs to be generated by supplying the same current to the quadrupole magnets A102 and I302; a symmetrical focusing magnetic field needs to be generated by supplying the same current to the quadrupole magnets B1103 and H301; a symmetrical focusing magnetic field needs to be generated by supplying the same current to the quadrupole magnets D106 and G202; and a symmetrical focusing magnetic field needs to be generated by supplying the same current to the quadrupole magnets E107 and F201. The current supplied to these magnets should ensure that the superimposed magnetic field generated can restrict the beam's smooth transmission in the pipe and achieve the function of eliminating dispersion.

[0042] In this embodiment, by superimposing symmetrical achromatic extension structures and antisymmetric achromatic extension structures, multiple directions of beam deflection and transmission can be achieved under the condition that the beam dispersion function is zero. In addition, repeatedly superimposing symmetrical achromatic extension structures and antisymmetric achromatic extension structures can achieve deflection and beam transmission in more directions, meeting the construction needs of large, medium and small hospitals and research institutions to build multi-treatment terminal proton therapy systems.

[0043] As can be seen from Examples 1 and 2, this utility model has a small footprint and a compact layout.

[0044] In this invention, the specifications of quadrupole magnets A 102, B 103, C 104, D 106, E 107, F 201, G 202, H 301, I 302, and the first terminal quadrupole magnet 401 are all Q300, and the specifications of the second terminal quadrupole magnet 404 are all Q150. The specific parameters of the quadrupole magnets are shown in Table 1.

[0045]

[0046] In this utility model, the initial deflection secondary magnet 101, deflection secondary magnet A 105, deflection secondary magnet B 108, deflection secondary magnet C 203, and deflection secondary magnet D 303 are all of model B45, and their specific parameters are shown in Table 2.

[0047]

Claims

1. A compact multidirectional symmetric achromatic beam transport system, characterized by: The initial deflection two-stage magnet (101), the four-stage magnet A (102), the four-stage magnet B (103), the four-stage magnet C (104), and the deflection two-stage magnet A (105) are arranged in axial symmetry, forming a symmetric dispersionless structure. The initial deflection two-stage magnet (101), the four-stage magnet A (102), the four-stage magnet B (103), the four-stage magnet D (106), the four-stage magnet E (107), and the deflection two-stage magnet B (108) are arranged in central symmetry, forming an anti-symmetric dispersionless structure. The initial deflection two-stage magnet (101), the four-stage magnet A (102), the four-stage magnet B (103), the four-stage magnet F (201), the four-stage magnet G (202), and the deflection two-stage magnet C (203) are arranged in axial symmetry.

2. A compact multidirectional symmetric achromatic beam transport system according to claim 1, characterized in that: The initial deflection two-stage magnet (101), the four-stage magnet A (102), the four-stage magnet B (103), the four-stage magnet H (301), the four-stage magnet I (302), and the deflection two-stage magnet D (303) are arranged in central symmetry. The deflection two-stage magnet A (105), the deflection two-stage magnet B (108), the deflection two-stage magnet C (203), and the deflection two-stage magnet D (303) are respectively connected to the fixed experimental beam treatment terminal (400). The fixed experimental beam treatment terminal (400) is sequentially provided with two terminal first four-stage magnets (401), a vacuum chamber (403), two terminal second four-stage magnets (404), an X scanning magnet (406), a Y scanning magnet (407), a beam measurement system (408), and an isocenter (409) along the proton beam direction.

3. A compact multidirectional symmetric achromatic beam transport system according to claim 2, characterized in that: ​ 4. A compact multidirectional symmetric achromatic beam transport system according to claim 3, characterized in that: ​

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