Compact type multidirectional symmetrical de-dispersive beam transmission system
By adopting a compact multi-directional symmetric absent dispersion beam transmission system in proton therapy systems, and using symmetric or anti-symmetric structures to eliminate beam dispersion, the problem of insufficient layout of beam transmission lines of existing proton therapy systems is solved, and the construction of a proton therapy system with lower cost and higher flexibility is achieved.
Patent Information
- Application Number
- CN202510051081.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-13
- Publication Date
- 2025-03-07
Smart Images
Figure CN119565043A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of radiotherapy, and in particular relates to a compact multi-directional symmetrical achromatic beam transmission system. Background Art
[0002] The proton therapy system uses proton beams to irradiate tumor lesions. After being accelerated by an accelerator, protons modulate their energy in an energy selection system, and are then transported by a beam transmission system to the treatment terminal before entering the human body. At the beginning of entering the human body, the energy released by proton beams is very limited, but after reaching a certain depth, the beams will instantly release a large amount of energy, forming an energy release trajectory in the shape of a "Bragg peak". Using this feature, proton beams can irradiate tumor lesions with high doses while avoiding normal human tissues. This maximizes the therapeutic effect while reducing the side effects of treatment.
[0003] A compact and flexible proton therapy beam transmission system that can reduce the number of transmission line components is one of the urgent needs for future medical and scientific research institutions to widely build proton therapy centers.
[0004] Dispersion is a relatively important parameter in the beam transmission process. It can reflect the relationship between the momentum dispersion of the beam and the size of the beam envelope. Eliminating dispersion can achieve decoupling between the momentum dispersion of the beam and the lateral envelope, which is beneficial to the transmission of the beam and can better match the beam requirements at the treatment terminal. Therefore, corresponding structures need to be set in the beam transmission line of the proton therapy system to eliminate dispersion to ensure that the dispersion function of the treatment terminal beam is zero.
[0005] The beam transmission line of a traditional multi-terminal proton therapy system often uses a long straight beam transmission section with zero dispersion function as the main beam transmission line, and the beams of each treatment terminal are all drawn out from the main beam transmission line. In the process of drawing out the beam from each treatment terminal, dispersion is introduced due to the deflection of the beam, so an additional de-dispersion structure is required to eliminate the dispersion. The long straight beam transmission section greatly limits the flexibility of the beam transmission line layout; the additional magnet components also increase the cost of proton therapy facilities.
[0006] How to realize the layout of multi-terminal beam transmission lines under limited and complex building conditions, form a construction plan for a compact and multi-purpose proton therapy system, and meet the cost expectations and clinical research needs of various institutions is one of the important directions of the current research and development of key proton therapy technologies. Summary of the invention
[0007] The purpose of the present invention is to provide a compact multi-directional symmetrical achromatic beam transmission system to solve the problem that the existing proton beam transmission line layout is not compact and flexible enough and the cost is high.
[0008] The technical solution of the present invention is: a compact multi-directional symmetrical achromatic beam transmission system, wherein an initial deflection secondary magnet, a quadruple magnet A, a quadruple magnet B, a quadruple magnet C, a deflection secondary magnet A, a quadruple magnet D, a quadruple magnet E and a deflection secondary magnet B are sequentially arranged along the proton beam direction; The initial deflection secondary magnet, the quadruple magnet A, the quadruple magnet B, the quadruple magnet C and the deflection secondary magnet A are arranged axially symmetrically to form a symmetrical achromatic structure; The initial deflection secondary magnet, the quadrupole magnet A, the quadrupole magnet B, the quadrupole magnet D, the quadrupole magnet E and the deflection secondary magnet B are arranged in a centrally symmetrical manner to form an antisymmetric achromatic structure.
[0009] As a further improvement of the present invention, one or more symmetric achromatic extension units and one or more antisymmetric achromatic extension units are further provided at the rear end of the deflection secondary magnet B; The symmetrical achromatic extension unit is provided with a quadrupole magnet F, a quadrupole magnet G and a deflection secondary magnet C in sequence along the proton beam direction, and the initial deflection secondary magnet, the quadrupole magnet A, the quadrupole magnet B, the quadrupole magnet F, the quadrupole magnet G and the deflection secondary magnet C are arranged in an axisymmetric manner; The antisymmetric achromatic stretching unit is provided with a quadrupole magnet H, a quadrupole magnet I and a deflection secondary magnet D in sequence along the proton beam direction, and the initial deflection secondary magnet, the quadrupole magnet A, the quadrupole magnet B, the quadrupole magnet H, the quadrupole magnet I and the deflection secondary magnet D are arranged in a centrally symmetrical manner.
[0010] As a further improvement of the present invention, the deflection secondary magnet A, the deflection secondary magnet B, the deflection secondary magnet C, and the deflection secondary magnet D are respectively connected to the fixed experimental beam treatment terminal.
[0011] As a further improvement of the present invention, the fixed experimental beam therapy terminal is sequentially 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 an isocenter along the proton beam direction.
[0012] Compared with the traditional multi-terminal proton therapy system beam transmission line design, the present invention has the following advantages: 1. Different from the traditional layout method of setting a long straight main beam transmission section and using a dispersive structure to eliminate the dispersion function introduced by deflecting the beam to the auxiliary transmission section, the present invention uses a symmetrical or anti-symmetrical structure to eliminate beam dispersion while deflecting the beam to the auxiliary transmission section (treatment terminal), so that the deflected beam does not need to pass through the dispersive structure again to meet the treatment terminal requirements. This technical solution reduces the additional space occupation and equipment used by each treatment terminal under the traditional layout, which requires each treatment terminal to have its own dispersive structure, effectively reduces the construction cost of the proton therapy system and improves the flexibility of the layout.
[0013] 2. The symmetric achromatic extension unit and the antisymmetric achromatic extension unit in the present invention can be arbitrarily superimposed and used according to the actual building layout and the number of treatment terminals required, and can form a beam transmission line layout with multiple deflection directions and multiple branches, which is conducive to the flexible arrangement of beam transmission lines in large, medium and small hospitals and scientific research institutions, and realizes the construction of a multi-terminal and multi-purpose proton therapy system under the conditions of complex building space and limited budget. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a structural schematic diagram of a first embodiment of the present invention; Figure 2 is a schematic diagram of introducing a dispersion function in a first embodiment of the present invention; Figure 3 is a dispersion function diagram of a first embodiment of the present invention; Figure 4 It is a structural schematic diagram of a second embodiment of the present invention.
[0015] In the figure: 101-initial deflection secondary magnet; 102-quadrupole magnet A; 103-quadrupole magnet B; 104-quadrupole magnet C; 105-deflection secondary magnet A; 106-quadrupole magnet D; 107-quadrupole magnet E; 108-deflection secondary magnet B; 200-symmetric achromatic extension unit; 201-quadrupole magnet F, 202-quadrupole magnet G; 203-deflection secondary magnet C; 300-antisymmetric achromatic extension unit; 301-quadrupole magnet H; 302-quadrupole magnet I; 303-deflection secondary magnet D; 400-fixed experimental beam therapy terminal; 401-terminal first quadrupole magnet; 403-vacuum chamber; 404-terminal second quadrupole magnet; 406-X scanning magnet; 407-Y scanning magnet; 408-beam current measurement system; 409-isocenter. DETAILED DESCRIPTION
[0016] The present invention is further described in detail below through the accompanying drawings and specific embodiments.
[0017] Embodiment 1, like Figure 1As shown, a compact multi-directional symmetrical achromatic beam transmission system is provided, wherein an initial deflection secondary magnet 101, a quadrupole magnet A 102, a quadrupole magnet B 103, a quadrupole magnet C 104, a deflection secondary magnet A 105, a quadrupole magnet D 106, a quadrupole magnet E 107 and a deflection secondary magnet B 108 are sequentially arranged along the proton beam direction; the initial deflection secondary magnet 101, the quadrupole magnet A 102, the quadrupole magnet B 103, the quadrupole magnet C 104 and the deflection secondary magnet A 105 are arranged axially symmetrically to form a symmetrical achromatic structure; the initial deflection secondary magnet 101, the quadrupole magnet A 102, the quadrupole magnet B 103, the quadrupole magnet D 106, the quadrupole magnet E 107 and the deflection secondary magnet B 108 are arranged centrally symmetrically to form an antisymmetric achromatic structure.
[0018] By arranging the deflection dipole magnet and the quadrupole magnet in an axisymmetric (symmetric achromatic structure) or a center-symmetric (antisymmetric achromatic structure), the beam can be deflected when the dispersion of the beam is zero after deflection. When operating the beam deflection, it is necessary to provide the same current to the deflection secondary magnets at symmetrical positions in the structure to generate a symmetrical deflection magnetic field, and to provide the same current to the quadrupole magnets at symmetrical positions in the structure to generate a symmetrical focusing magnetic field. The details are as follows: When the symmetrical achromatic structure is in operation to deflect the beam, it is necessary to provide the same current to the initial deflection secondary magnet 101 and the deflection secondary magnet A105 to generate a symmetrical deflection magnetic field, and to provide the same current to the quadrupole magnet A102 and the quadrupole magnet C104 to generate a symmetrical focusing magnetic field. The current provided to the above magnets should ensure that the superimposed magnetic field generated by them can limit the smooth transmission of the beam in the pipeline and realize the function of eliminating dispersion.
[0019] When the antisymmetric achromatic dispersion structure is in operation to deflect the beam, the quadrupole magnet C 104 and the deflection secondary magnet A 105 do not work, and the same current is required to be provided to the initial deflection secondary magnet 101 and the deflection secondary magnet B 108 to generate a symmetrical deflection magnetic field, the same current is required to be provided to the quadrupole magnet A 102 and the quadrupole magnet 107 to generate a symmetrical focusing magnetic field, and the same current is required to be provided to the quadrupole magnet B 103 and the quadrupole magnet D 106 to generate a symmetrical focusing magnetic field. The current provided to the above magnets should ensure that the superimposed magnetic field generated by them can limit the smooth transmission of the beam in the pipeline and realize the function of eliminating dispersion.
[0020] This embodiment can provide two fixed beam treatment rooms, and the deflection secondary magnet A 105 and the deflection secondary magnet B 108 are respectively connected to the fixed experimental beam treatment terminal 400. The fixed experimental beam treatment terminal 400 is provided 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 409 in sequence along the proton beam direction. The first quadrupole magnet 401 at the terminal is used to control the beam envelope of the deflected beam; the vacuum chamber group 403 is used for evacuation, and is also equipped with a fluorescent target and a Faraday cage, which are used to monitor the beam state when the entire proton beam system is running and block the proton beam when the entire proton beam system needs to stop the beam, and block the beam in front of the treatment room; the second quadrupole magnet 404 at the terminal is used to control the beam so that it converges into a beam spot of the required size at the isocenter; 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 achieve an active point scanning irradiation field of no less than 30cm×40cm, and deliver the proton beam to the isocenter 409.
[0021] The symmetric achromatic structure and the antisymmetric achromatic structure respectively adopt the symmetric achromatic principle and the antisymmetric achromatic principle to achieve beam deflection and transmission under the condition of eliminating dispersion in a limited building layout.
[0022] In this embodiment, the dispersion function is introduced when the main beam transmission section is deflected (point 1), and the dispersion function is eliminated when entering the auxiliary transmission section of branch 1 (point 2) and the auxiliary transmission section of branch 2 (point 4). The dispersion function is 0 at the treatment terminal of branch 1 (point 3) and the treatment terminal of branch 2 (point 5). Figure 2 , Figure 3 Here, the secondary transmission section connected to the deflection secondary magnet A 105 is branch 1, and the secondary transmission section connected to the deflection secondary magnet B 108 is branch 2.
[0023] Embodiment 2, like Figure 4As shown, the difference between this embodiment and embodiment 1 is that: a symmetric achromatic extension unit 200 and an antisymmetric achromatic extension unit 300 are further provided at the rear end of the deflection secondary magnet B 108; the symmetric achromatic extension unit 200 is sequentially provided with a quadrupole magnet F 201, a quadrupole magnet G 202 and a deflection secondary magnet C 203 along the direction of the proton beam, and the initial deflection secondary magnet 101, the quadrupole magnet A 102, the quadrupole magnet B 103, the quadrupole magnet F 201, the quadrupole magnet G 202 and the deflection secondary magnet C 203 are arranged in an axisymmetric manner; the antisymmetric achromatic extension unit 300 is sequentially provided with a quadrupole magnet H 301, a quadrupole magnet I 302 and a deflection secondary magnet D 303 along the direction of the proton beam, and the initial deflection secondary magnet 101, the quadrupole magnet A 102, the quadrupole magnet B 103, the quadrupole magnet H 301, the quadrupole magnet I The deflection secondary magnet C 202 and the deflection secondary magnet D 303 are arranged in a central symmetric manner. The deflection secondary magnet C 203 and the deflection secondary magnet D 303 are respectively connected to the fixed experimental beam treatment terminal 400. This embodiment can provide 4 fixed beam treatment rooms.
[0024] The initial deflection secondary magnet 101, quadrupole magnet A 102, quadrupole magnet B 103, quadrupole magnet D 106, quadrupole magnet E 107, quadrupole magnet F 201, quadrupole magnet G 202 and the deflection secondary magnet C 203 form a symmetrical achromatic extension structure.
[0025] The initial deflection secondary magnet 101, quadrupole magnet A 102, quadrupole magnet B 103, quadrupole magnet D 106, quadrupole magnet E 107, quadrupole magnet F 201, quadrupole magnet G 202, quadrupole magnet H 301, quadrupole magnet I 302 and the deflection secondary magnet D 303 constitute an antisymmetric achromatic stretch structure.
[0026] Similarly, when operating the deflection beam, it is necessary to provide the same magnitude current to the deflection secondary magnets at symmetrical positions in the structure to generate a symmetrical deflection magnetic field, and to provide the same magnitude current to the symmetrical quadruple magnets at symmetrical positions in the structure to generate a symmetrical focusing magnetic field. The details are as follows: When the symmetrical achromatic structure is in operation to deflect the beam, it is necessary to provide the same current to the initial deflection secondary magnet 101 and the deflection secondary magnet A105 to generate a symmetrical deflection magnetic field, and provide the same current to the quadrupole magnet A102 and the quadrupole magnet C104 to generate a symmetrical focusing magnetic field. The current provided to the above magnets should ensure that the magnetic field generated by them can ensure that the beam is smoothly transmitted in the pipeline and can realize the dispersion elimination function of the symmetrical achromatic structure.
[0027] When the antisymmetric achromatic structure is in operation to deflect the beam, the quadrupole magnet C 104 and the deflection secondary magnet A 105 do not work, and the same current is required to be provided to the initial deflection secondary magnet 101 and the deflection secondary magnet B 108 to generate a symmetrical deflection magnetic field, the same current is required to be provided to the quadrupole magnet A 102 and the quadrupole magnet E 107 to generate a symmetrical focusing magnetic field, and the same current is required to be provided to the quadrupole magnet B 103 and the quadrupole magnet D 106 to generate a symmetrical focusing magnetic field. The current provided to the above magnets should ensure that the magnetic field generated by them can ensure that the beam is smoothly transmitted in the pipeline and can realize the dispersion elimination function of the symmetrical achromatic structure.
[0028] When the symmetrical achromatic dispersion stretching structure operates to deflect the beam, the quadrupole magnet C 104, the deflection secondary magnet A 105, and the deflection secondary magnet B 108 do not work, and the same current is required to be provided to the initial deflection secondary magnet 101 and the deflection secondary magnet C 203 to generate a symmetrical deflection magnetic field, the same current is required to be provided to the quadrupole magnet A 102 and the quadrupole magnet G 202 to generate a symmetrical focusing magnetic field, the same current is required to be provided to the quadrupole magnet B 103 and the quadrupole magnet F 201 to generate a symmetrical focusing magnetic field, and the same current is required to be provided to the quadrupole magnet D 106 and the quadrupole magnet E 107 to generate a symmetrical focusing magnetic field. The current provided to the above magnets should ensure that the superimposed magnetic field generated by them can limit the smooth transmission of the beam in the pipeline and realize the function of eliminating dispersion.
[0029] When the antisymmetric achromatic dispersion stretching structure operates to deflect the beam, the quadrupole magnet C 104, the deflection secondary magnet A 105, the deflection secondary magnet B 108, and the deflection secondary magnet C 203 do not work, and the same current is required to be provided to the initial deflection secondary magnet 101 and the deflection secondary magnet D 303 to generate a symmetrical deflection magnetic field, the same current is required to be provided to the quadrupole magnet A 102 and the quadrupole magnet I 302 to generate a symmetrical focusing magnetic field, the same current is required to be provided to the quadrupole magnet B 1 103 and the quadrupole magnet H 301 to generate a symmetrical focusing magnetic field, the same current is required to be provided to the quadrupole magnet D 106 and the quadrupole magnet G 202 to generate a symmetrical focusing magnetic field, the same current is required to be provided to the quadrupole magnet E 107 and the quadrupole magnet F 201 to generate a symmetrical focusing magnetic field, and the current provided to the above magnets should ensure that the superimposed magnetic field generated by them can limit the smooth transmission of the beam in the pipeline and realize the function of eliminating dispersion.
[0030] In this embodiment, by superimposing a symmetric achromatic stretch structure and an antisymmetric achromatic stretch structure, beam deflection and transmission in multiple directions can be achieved under the condition that the deflected beam dispersion function is zero. In addition, repeated superposition of a symmetric achromatic stretch structure and an antisymmetric achromatic stretch structure can achieve deflection and beam transmission in more directions, meeting the construction needs of large, medium and small hospitals and scientific research institutions for building multi-treatment terminal proton therapy systems.
[0031] It can be seen from Examples 1 and 2 that the present invention occupies a small area and has a compact layout.
[0032] In the present invention, the specifications of the quadrupole magnet A 102, the quadrupole magnet B 103, the quadrupole magnet C 104, the quadrupole magnet D 106, the quadrupole magnet E 107, the quadrupole magnet F 201, the quadrupole magnet G 202, the quadrupole magnet H 301, the quadrupole magnet I 302, and the first quadrupole magnet 401 at the terminal are all Q300, and the specifications of the second quadrupole magnet 404 at the terminal are all Q150. The specific parameters of the quadrupole magnets are shown in Table 1.
[0033] In the present invention, the specification model of the initial deflection secondary magnet 101, the deflection secondary magnet A 105, the deflection secondary magnet B 108, the deflection secondary magnet C 203, and the deflection secondary magnet D 303 is B45, and the specific parameters are shown in Table 2.
Claims
1. A compact multi-directional symmetric achromatic beam transmission system, characterized by: An initial deflection secondary magnet (101), a quadrupole magnet A (102), a quadrupole magnet B (103), a quadrupole magnet C (104), a deflection secondary magnet A (105), a quadrupole magnet D (106), a quadrupole magnet E (107) and a deflection secondary magnet B (108) are sequentially arranged along the proton beam direction; The initial deflection secondary magnet (101), the quadruple magnet A (102), the quadruple magnet B (103), the quadruple magnet C (104) and the deflection secondary magnet A (105) are arranged in an axisymmetric manner to form a symmetrical achromatic structure; The initial deflection secondary magnet (101), the quadrupole magnet A (102), the quadrupole magnet B (103), the quadrupole magnet D (106), the quadrupole magnet E (107) and the deflection secondary magnet B (108) are arranged in a centrally symmetrical manner to form an antisymmetric achromatic structure.
2. A compact multi-directional symmetric achromatic beam transmission system according to claim 1, characterized in that: One or more symmetric achromatic extension units (200) and one or more antisymmetric achromatic extension units (300) are also provided at the rear end of the deflection secondary magnet B (108); The symmetrical achromatic extension unit (200) is provided with a quadrupole magnet F (201), a quadrupole magnet G (202) and a deflection secondary magnet C (203) in sequence along the proton beam direction, wherein the initial deflection secondary magnet (101), the quadrupole magnet A (102), the quadrupole magnet B (103), the quadrupole magnet F (201), the quadrupole magnet G (202) and the deflection secondary magnet C (203) are arranged in an axisymmetric manner; The antisymmetric achromatic extension unit (300) is provided with a quadrupole magnet H (301), a quadrupole magnet I (302) and a deflection secondary magnet D (303) in sequence along the proton beam direction, and the initial deflection secondary magnet (101), the quadrupole magnet A (102), the quadrupole magnet B (103), the quadrupole magnet H (301), the quadrupole magnet I (302) and the deflection secondary magnet D (303) are arranged in a centrally symmetrical manner.
3. A compact multi-directional symmetric achromatic beam transmission system according to claim 2, characterized in that: The deflection secondary magnet A (105), the deflection secondary magnet B (108), the deflection secondary magnet C (203), and the deflection secondary magnet D (303) are respectively connected to the fixed experimental beam treatment terminal (400).
4. A compact multi-directional symmetric achromatic beam transmission system according to claim 3, characterized in that: The fixed experimental beam treatment terminal (400) is provided 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 (409) in sequence along the proton beam direction.