Integrated scanning magnet and proton heavy ion therapy device

Abstract

The application provides an integrated scanning magnet and a proton heavy ion treatment device, which can be applied to the technical field of particle accelerators. The integrated scanning magnet comprises a core, a first scanning coil, a second scanning coil group, a three-dimensional adjustable base and a water distributor. The first scanning coil is symmetrically arranged along a first horizontal direction perpendicular to the propagation direction of the beam, and is used for generating a first deflection magnetic field along the first horizontal direction. The second scanning coil group is symmetrically arranged along a second horizontal direction perpendicular to the propagation direction of the beam, and is used for generating a second deflection magnetic field along the second horizontal direction. The second scanning coil group comprises a first group of coils and a second group of coils, and the second group of coils is used for optimizing the excitation efficiency of the window frame core. The core adopts a window frame structure, and the end plate and the core body are communicated with a slot to reduce the eddy current loss. The X and Y direction scanning coils are integrated in the same core, the Z direction size of the treatment head is significantly shortened, and the weight of the rotating gantry is reduced.

Description

Technical Field

[0001] This invention relates to the field of particle accelerator technology, and more specifically to an integrated scanning magnet and proton and heavy ion therapy device. Background Technology

[0002] Proton and heavy ion therapy devices generate high-energy particle beams through accelerators to precisely irradiate tumor lesions. The rotating gantry is the core component for achieving multi-angle irradiation, and its miniaturization and weight reduction are important development directions for next-generation ion radiotherapy devices.

[0003] Currently, proton and heavy ion therapy devices typically employ two orthogonal, independent scanning magnets on their rotating gantry to control the deflection of the beam in the X and Y directions, respectively. During operation, the beam passes sequentially through the two magnets; the X-direction scanning magnet controls the beam deflection in the Y direction, and the Y-direction scanning magnet controls the beam deflection in the X direction, thus achieving pencil beam scanning.

[0004] However, this split structure has the following technical problems:

[0005] First, the Z-axis dimension is too large. A drift segment needs to be set between the two independent scanning magnets to meet the requirements of magnetic field isolation and beam transmission, which leads to a significant increase in the length of the entire treatment head in the beam direction. For a rotating gantry, the increased length of the treatment head will directly increase the rotation radius of the gantry, thereby causing a sharp increase in the size and weight of the gantry.

[0006] Second, beam control precision is limited. In a split structure, the beam is uncontrolled within the drift segment between the two magnets and is prone to deviation due to space charge effects or residual magnetic fields, resulting in decreased beam spot uniformity and positioning accuracy, thus affecting treatment efficacy.

[0007] Third, the system has low integration, which is not conducive to lightweight design. Each of the two independent magnets requires its own iron core, coil, and cooling system, resulting in high structural redundancy and making it difficult to achieve the overall lightweight goal.

[0008] Therefore, how to eliminate the drift segment between two independent scanning magnets, achieve the integrated integration of X and Y deflection magnetic fields, compress the Z-direction space to the extreme while ensuring beam deflection performance, and achieve the lightweighting of the scanning magnets are technical problems that urgently need to be solved in this field. Summary of the Invention

[0009] (a) Technical problems to be solved

[0010] To address at least one of the aforementioned problems, this invention provides an integrated scanning magnet and proton and heavy ion therapy device. Through multiple technological innovations, such as integrated design, dual-coil excitation optimization, end plate slotting to reduce eddy currents, and coil shape optimization, the scanning magnet is made lighter and smaller, while effectively improving beam control accuracy and system reliability, providing important technical support for the development of proton and heavy ion therapy devices.

[0011] (II) Technical Solution

[0012] To address the aforementioned technical problems, embodiments of the present invention propose an integrated scanning magnet and proton / heavy ion therapy device.

[0013] According to a first aspect of the present invention, an integrated scanning magnet is provided, comprising: an iron core; a first scanning coil disposed inside the iron core, the first scanning coil being symmetrically arranged along a first horizontal direction perpendicular to the beam propagation direction, for generating a first deflection magnetic field along the first horizontal direction to drive a particle beam to scan along a second horizontal direction perpendicular to the first horizontal direction; and a second scanning coil group disposed inside the iron core, the second scanning coil group being symmetrically arranged along a second horizontal direction perpendicular to the beam propagation direction, for generating a second deflection magnetic field along the second horizontal direction to drive a particle beam to scan along the first horizontal direction; wherein the second scanning coil group includes a first group of coils and a second group of coils, the second group of coils being used to optimize the excitation efficiency of the iron core; the first horizontal direction and the second horizontal direction are orthogonal to each other.

[0014] In some exemplary embodiments, the core adopts a window frame structure, with the left and right halves of the core symmetrically forming a closed magnetic circuit.

[0015] In some exemplary embodiments, the end plate of the iron core is connected to the iron core body by slots, and the slots are arranged in a preset shape to reduce the eddy currents generated by the end magnetic field at a fast scanning frequency and reduce the temperature rise of the iron core.

[0016] In some exemplary embodiments, the integrated scanning magnet further includes a three-dimensional adjustable base, which is fixed to the bottom of the iron core for connection with the rotating frame and supports fine adjustment in the X, Y, and Z directions to calibrate the positional deviation between the magnet center and the beam center.

[0017] In some exemplary embodiments, the integrated scanning magnet further includes a water distributor mounted on the upper and lower bottom surfaces of the iron core, for uniformly distributing the cooling medium of the external cooling system to the first scanning coil and the second scanning coil group.

[0018] In some exemplary embodiments, the shape and position of the first scanning coil and the second scanning coil group are optimized through three-dimensional magnetic field calculation, so that the magnetic field uniformity within the good field area reaches ±5×10⁻⁶. -3 .

[0019] In some exemplary embodiments, both the first scanning coil and the second scanning coil group are made of hollow wire with an outer square and an inner circle, and the hollow wire is filled with a cooling medium.

[0020] In some exemplary embodiments, the core is made of high-permeability silicon steel sheets laminated together, the high-permeability silicon steel sheets having a thickness of 0.35 mm and being cold-rolled non-oriented silicon steel sheets.

[0021] In some exemplary embodiments, the iron core is cast separately from the first scanning coil and the second scanning coil group to facilitate individual replacement of the iron core or the coil.

[0022] According to a first aspect of the present invention, a proton and heavy ion therapy apparatus is provided, comprising: a rotating gantry; and the aforementioned integrated scanning magnet, the integrated scanning magnet being mounted on the rotating gantry for controlling the deflection direction of the beam.

[0023] (III) Beneficial Effects

[0024] As can be seen from the above technical solution, the integrated scanning magnet and proton / heavy ion therapy device provided by the embodiments of the present invention has at least the following beneficial effects:

[0025] (1) Significantly shortening the Z-axis dimension of the treatment head, achieving miniaturization of the rotating gantry. This invention integrates the X-axis scanning coil and the Y-axis scanning coil into the same iron core, eliminating the drift segment between the two independent magnets in the traditional separate structure, thus greatly reducing the length of the treatment head in the beam direction. For the rotating gantry, the reduction in treatment head length directly reduces the rotation radius, thereby effectively reducing the gantry volume and weight, providing key technical support for the miniaturization and lightweighting of the next generation of ion radiotherapy devices.

[0026] (2) Improve beam control accuracy and irradiation uniformity. The present invention achieves X and Y orthogonal deflection within the same magnetic circuit, eliminating the need for the beam to propagate freely within the drift segment. This avoids beam offset caused by space charge effect or residual magnetic field, effectively reducing beam transmission error and significantly improving the positioning accuracy and irradiation uniformity of pencil beam scanning, thereby enhancing the treatment effect.

[0027] (3) Optimize excitation efficiency and improve magnetic field performance. The present invention adopts a double coil structure in the Y direction. By adding a second coil, the excitation efficiency of the window frame core is optimized, and the magnetic field performance is improved within the limited core space, solving the problem of insufficient magnetic field strength after integrated design.

[0028] (4) Effectively control the core temperature rise and reduce operational risks. The present invention opens slots arranged in a preset shape at the connection between the core end plate and the core body, which effectively reduces the eddy currents generated by the end magnetic field at the fast scanning frequency, significantly reduces the core temperature rise, and avoids the risk of damaging the coil insulation due to excessive local temperature rise. At the same time, the end plate thickness is optimized through simulation verification, and the core weight is further reduced while ensuring structural strength.

[0029] (5) Achieving high-precision magnetic field uniformity and ensuring beam deflection quality. This invention optimizes the shape and position of the first and second scanning coil groups through three-dimensional magnetic field calculation, so that the magnetic field uniformity within the good field area reaches ±5×10 -3 Meanwhile, the magnetic field uniformity can be calibrated by adjusting the coil position based on the test results, ensuring the stability and consistency of the beam deflection.

[0030] (6) Achieve lightweight design and reduce rack load. This invention eliminates redundant structure through integrated design. Combined with window frame type iron core, optimized end plate thickness, and high permeability silicon steel sheet stacking processing, the weight is expected to be only two-thirds of that of traditional independent scanning magnets, which significantly reduces the load on the rotating rack and creates conditions for simplifying the rack drive system and reducing energy consumption.

[0031] (7) Improve system maintainability and reduce the risk of going online. The present invention casts the iron core and coil separately, which makes it easy to replace the iron core or coil individually and reduces the equipment maintenance cost; the three-dimensional adjustable base supports fine adjustment in the X, Y and Z directions, which can accurately calibrate the positional deviation between the magnet center and the beam center, ensuring that the magnetic field deflection direction is accurately matched with the beam trajectory, reducing the difficulty of system assembly and debugging. Attached Figure Description

[0032] The above-described features, other objects, and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0033] Figure 1 A schematic diagram of the structure of an integrated scanning magnet according to an embodiment of the present invention is shown.

[0034] Figure 2 A schematic cross-sectional view of an integrated scanning magnet according to an embodiment of the present invention is shown.

[0035] Figure 3A schematic diagram of the structure of a first scanning coil according to an embodiment of the present invention is shown;

[0036] Figure 4 A schematic diagram of the structure of the second scanning coil group according to an embodiment of the present invention is shown;

[0037] Figure 5 A schematic diagram of the core structure of an integrated scanning magnet according to an embodiment of the present invention is shown.

[0038] Figure label:

[0039] 1-Iron core; 1-1-Left half iron core; 1-2 Right half iron core; 2-First scanning coil; 3-First group of coils; 4-Second group of coils; 5-Three-dimensional adjustable base; 6-Water distributor. Detailed Implementation

[0040] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0041] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0042] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0043] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0044] Figure 1 A schematic diagram of the structure of an integrated scanning magnet according to an embodiment of the present invention is shown.

[0045] like Figure 1 and Figure 2 As shown, the integrated scanning magnet of this embodiment includes an iron core 1, a first scanning coil 2, a second scanning coil group, a three-dimensional adjustable base 5, and a water separator 6. The second scanning coil group includes a first group of coils 3 and a second group of coils 4. For ease of description, the beam propagation direction is defined as the Z-axis direction. A first horizontal direction and a second horizontal direction, orthogonal to each other, are defined in a horizontal plane perpendicular to the beam propagation direction. The first horizontal direction corresponds to the X-axis direction, and the second horizontal direction corresponds to the Y-axis direction. The core of this invention lies in integrating the X-direction scanning coil and the Y-direction scanning coil into the same iron core and employing a dual-coil structure to optimize excitation efficiency. This eliminates the drift segment between the two independent magnets in the traditional separate structure, achieving an integrated design of the X and Y deflection magnetic fields. This significantly shortens the length of the treatment head in the beam direction, providing key technical support for the miniaturization and weight reduction of the rotating gantry.

[0046] In an embodiment of the invention, a first scanning coil 2 is disposed inside the iron core 1 and symmetrically arranged along a first horizontal direction (i.e., the X-axis direction) to generate a deflection magnetic field along the first horizontal direction (i.e., the X-axis direction), driving the particle beam to scan along a second horizontal direction (i.e., the Y-axis direction). A second scanning coil group is disposed inside the iron core 1 and symmetrically arranged along the second horizontal direction (i.e., the Y-axis direction) to generate a deflection magnetic field along the second horizontal direction (i.e., the Y-axis direction), driving the particle beam to scan along the first horizontal direction (i.e., the X-axis direction). The two sets of coils are orthogonally distributed in space, realizing decoupling control of the magnetic fields in the X and Y directions, ensuring that the deflection of the beam in the two directions is independent and does not interfere with each other.

[0047] Figure 3 A schematic diagram of the structure of a first scanning coil according to an embodiment of the present invention is shown.

[0048] like Figure 3 As shown, the first scanning coil 2 is made of hollow copper wire with an outer square and an inner circle, and a cooling medium flows through the inside of the hollow wire. The outer square and inner circle cross-section design not only ensures the fill factor of the winding, enabling the coil to obtain sufficient ampere-turns in a limited space, but also provides a smooth flow channel for the cooling medium, ensuring that the Joule heat generated by the coil in the high-frequency pulse working mode can be carried away in time.

[0049] Figure 4 A schematic diagram of the structure of the second scanning coil group according to an embodiment of the present invention is shown.

[0050] like Figure 4As shown, the second scanning coil group adopts a dual-coil design. By adding a second coil 4, the excitation efficiency is effectively improved within the limited space of the window frame core, compensating for the potential problem of insufficient magnetic field strength after integrated design. Both the first coil 3 and the second coil 4 are made of hollow copper wire with an outer square and inner circle shape, and the hollow wire is filled with a cooling medium. The cooperative operation of the dual coils allows for a stronger deflection magnetic field to be obtained under the same excitation current, or to reduce the current density of a single coil when the same magnetic field strength is achieved, thereby reducing coil heating and improving system reliability.

[0051] In an embodiment of the present invention, the shape and position of the first scanning coil 2 and the second scanning coil group are optimized through three-dimensional magnetic field calculation, so that the magnetic field uniformity within the good field area reaches ±5×10. -3 Specifically, this invention employs the finite element method to establish a complete electromagnetic field model of the core, coil, and surrounding air domain. The standard deviation of the magnetic field distribution within the good field region is used as the objective function, with the coil's geometric dimensions, spatial location, and number of turns as design variables. An iterative optimization algorithm is then used to seek the optimal solution. This optimization process fully considers the nonlinear magnetization characteristics of the core material, the coil edge effect, and the influence of end leakage flux on the good field region, ensuring that the final determined coil shape and position achieve a highly uniform magnetic field distribution within the good field region.

[0052] The magnetic field uniformity can be calibrated by adjusting the positions of the first and second scanning coil groups based on the test results. This design improves the system's fault tolerance and maintainability. After actual assembly, the coil positions can be fine-tuned through a precision adjustment mechanism to compensate for accumulated errors generated during processing and assembly, ensuring that the magnetic field performance meets the standards and avoiding performance degradation and scrap losses due to manufacturing tolerances.

[0053] like Figure 3 and Figure 4 As shown, both the first and second scanning coil groups adopt irregular shapes to adapt to the internal space of the window-frame-shaped iron core, and the shape and position of the coils are optimized through three-dimensional magnetic field calculations. The irregular shape design breaks through the limitations of traditional rectangular coils, providing more degrees of freedom for optimizing magnetic field uniformity, allowing the geometry of the coil to be precisely matched with the magnetic circuit structure of the iron core, thereby achieving better uniformity indicators while maintaining high magnetic field strength.

[0054] Figure 5 A schematic diagram of the core structure of an integrated scanning magnet according to an embodiment of the present invention is shown. Figure 5As shown, core 1 adopts a window-frame structure, with the left half of core 1-1 and the right half of core 1-2 symmetrically forming a closed magnetic circuit. The window-frame core design replaces the traditional H-type core, solving the problem of optimizing magnetic field uniformity caused by the increased air gap in integrated designs. The symmetrical structure ensures the symmetry of the magnetic circuit, so that the magnetic fields generated by the left and right half of cores have good central symmetry after superposition in the air gap, which is beneficial for the alignment and maintenance of the beam center.

[0055] The core material is made of high-permeability silicon steel sheets laminated together. The silicon steel sheets are 0.35mm thick and are made of cold-rolled non-oriented silicon steel sheets to reduce hysteresis loss and eddy current loss, ensuring magnetic field response speed and adapting to pulse operation mode. The lamination process insulates the silicon steel sheets from each other, effectively suppressing the propagation of eddy currents between the sheets and further reducing iron loss during high-frequency operation.

[0056] The end plates of the iron core are connected to the core body and have slots arranged in a preset shape. These slots are used to reduce eddy currents generated by the end magnetic field at high scanning frequencies, thereby reducing the temperature rise of the iron core. This slotting design is one of the key innovations of this invention. By disrupting the continuity of the eddy current loop, the macroscopic eddy currents originally formed in the end plates are divided into multiple micro-eddy currents, significantly reducing the eddy current path length and eddy current losses, and avoiding the risk of damage to the coil insulation due to excessive local temperature rise. The thickness of the end plates is determined through simulation verification. The end plate thickness is reduced while ensuring structural strength to reduce the overall weight of the iron core, while balancing eddy current losses and structural rigidity.

[0057] In this embodiment of the invention, a three-dimensional adjustable base 5 is fixed to the bottom of the iron core 1 for connection to the rotating frame. It supports fine-tuning in the X, Y, and Z directions to calibrate the positional deviation between the magnet center and the beam center, ensuring precise matching between the magnetic field deflection direction and the beam trajectory. This base achieves independent adjustment in three directions through a precision threaded adjustment mechanism, with adjustment accuracy down to the micrometer level, significantly reducing the difficulty of system assembly and debugging. The design of the three-dimensional adjustable base allows for fine adjustment of the magnet based on beam optical measurement results even after installation, improving the system's engineering adaptability.

[0058] In an embodiment of the invention, a water distributor 6 is installed on the upper and lower bottom surfaces of the iron core 1, respectively, to evenly distribute deionized water from the external cooling system to the first scanning coil 2 and the second scanning coil group, thereby dissipating heat from the coils, reducing their operating temperature, and improving magnetic field stability. The water distributor adopts a multi-path balanced distribution design to ensure consistent cooling flow to each coil and prevent localized overheating. An internal flow regulating valve is provided in the water distributor to optimize flow distribution based on the actual heating conditions of each coil, achieving refined control of thermal management.

[0059] In this embodiment of the invention, the iron core is cast separately from the first scanning coil and the second scanning coil, facilitating individual replacement of the iron core or coil and reducing the risk of failure. This modular design eliminates the need for complete replacement during equipment maintenance, reducing maintenance costs and downtime. Furthermore, the separate casting process allows for separate quality inspection and performance testing of the iron core and coil, improving the reliability and yield of the manufacturing process.

[0060] The working principle of the integrated scanning magnet according to an embodiment of the present invention is as follows: When the first scanning coil is energized, a deflection magnetic field along the X direction is generated at the air gap of the iron core, which drives the particle beam to scan along the Y axis; when the second scanning coil group is energized, a deflection magnetic field along the Y direction is generated at the air gap of the iron core, which drives the particle beam to scan along the X axis. By controlling the magnitude and direction of the current in the first scanning coil and the second scanning coil group, precise scanning of the particle beam in the XY plane can be achieved, meeting the precise control requirements of pencil beam scanning therapy for beam position.

[0061] Because the first and second scanning coil groups are integrated within the same iron core, the drift segment between the two independent magnets in the traditional separate structure is eliminated, significantly shortening the length of the treatment head in the beam direction and achieving miniaturization and weight reduction of the rotating gantry. Simultaneously, a dual-coil design in the Y direction optimizes excitation efficiency through the second coil group, ensuring magnetic field strength. Slotted end plates on the iron core effectively suppress eddy current losses and control temperature rise. Optimized coil shape ensures magnetic field uniformity. A three-dimensional adjustable base ensures precise alignment of the magnetic center and beam center. A water separator provides efficient cooling. The separate casting design facilitates maintenance. The synergistic effect of these technical features makes the integrated scanning magnet of this invention superior to existing technologies in multiple dimensions, including size, weight, performance, reliability, and maintainability.

[0062] In one specific embodiment of the present invention, the aforementioned integrated scanning magnet is mounted on the rotating gantry of a proton and heavy ion therapy device to achieve pencil beam scanning irradiation. For example... Figure 1 As shown, the integrated scanning magnet is fixed inside the treatment head at the end of the rotating gantry via a three-dimensional adjustable base 5, with its beam injection direction coinciding with the axis of the treatment head. During treatment, the high-energy proton beam or heavy ion beam drawn from the accelerator is transmitted along the beamline, first entering the X-direction deflection magnetic field region generated by the first scanning coil 2, and obtaining scanning deflection in the Y direction; subsequently, it enters the Y-direction deflection magnetic field region generated by the second scanning coil group, and obtains scanning deflection in the X direction. By precisely controlling the excitation current of the two sets of scanning coils, the beam current forms a preset scanning pattern in the patient's target area, achieving conformal irradiation of the tumor lesion.

[0063] In this embodiment, since the first scanning coil 2 and the second scanning coil group are integrated within the same iron core 1, the drift segment between them is completely eliminated, and the free propagation distance between the beam deflection in the X direction and the Y direction is shortened to zero. This design significantly reduces the lateral divergence and space charge effect of the beam during propagation, improving the positioning accuracy of the scanning boundary. Clinical tests show that, after adopting the integrated scanning magnet of this invention, the dose drop width at the target area boundary of pencil beam scanning is reduced from 3-5 mm in the traditional scheme to less than 2 mm, significantly improving the conformity of the target area dose distribution and the protection effect on normal tissues.

[0064] Meanwhile, the integrated design significantly shortens the Z-axis length of the treatment head. Taking a typical proton therapy device as an example, the treatment head of a traditional separate scanning magnet structure is approximately 1200mm long. With the integrated scanning magnet of this invention, the treatment head length can be compressed to less than 800mm, a reduction of over 30%. This reduction in treatment head length directly decreases the rotation radius of the rotating gantry, thereby reducing the overall weight and moment of inertia of the gantry. For a 360° rotating gantry, every 100mm reduction in rotation radius reduces the total weight of the gantry by approximately 15-20 tons, while also correspondingly reducing the power requirements of the drive motor, making the miniaturization and weight reduction of the rotating gantry possible.

[0065] In this embodiment, the magnetic field uniformity index of the integrated scanning magnet directly affects the accuracy of the scanning boundary and the consistency of the dose distribution. Through three-dimensional magnetic field calculation optimization, the shape and position of the first scanning coil 2 and the second scanning coil group are precisely designed to achieve a magnetic field uniformity of ±5×10⁻⁶ within the good field region (typically defined as the area covered by the beam scanning range). -3 Taking a typical scanning range of 200mm×200mm as an example, this uniformity index ensures that the maximum deviation of the integrated magnetic field strength at each position of the scanning boundary does not exceed 0.5%, and the corresponding beam position deviation can be controlled within 0.1mm, which meets the stringent requirements of proton and heavy ion therapy for scanning accuracy.

[0066] In continuous operation mode, the Joule heat generated by the coil and the eddy current losses in the iron core may cause the magnet temperature to rise, leading to magnetic field drift and structural thermal deformation. In this embodiment, the water distributor 6 evenly distributes cooling water to the first scanning coil 2 and the second scanning coil group, effectively removing the coil heat; the slotted design of the iron core end plate significantly reduces end eddy current losses, keeping the temperature rise of the iron core below 100°C during long-term stable operation. Good thermal stability ensures the consistency of the magnetic field during long-term operation, allowing the treatment device to work continuously for several hours without recalibration.

[0067] In this embodiment, the modular design of separately casting the iron core and coil greatly facilitates on-site maintenance of the device. When it is necessary to replace the coil or iron core, it is not necessary to disassemble the entire treatment head; only the faulty component needs to be removed and replaced individually. The maintenance time is reduced from several days in the traditional solution to several hours, significantly improving the availability of the treatment device.

[0068] As can be seen from the above application examples, the integrated scanning magnet provided by the present invention has good applicability in proton and heavy ion therapy devices. While realizing the miniaturization and weight reduction of the treatment head, it effectively improves the accuracy and stability of beam scanning, providing reliable technical support for high-precision pencil beam scanning therapy.

[0069] Those skilled in the art will understand that the features described in the various embodiments of the present invention can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments of the present invention can be combined and / or combined in various ways without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

Claims

1. An integrated scanning magnet, characterized in that, include: Iron core; A first scanning coil is disposed inside the iron core. The first scanning coil is symmetrically arranged along a first horizontal direction perpendicular to the beam propagation direction to generate a first deflection magnetic field along the first horizontal direction to drive the particle beam to scan along a second horizontal direction perpendicular to the first horizontal direction. The second scanning coil group is disposed inside the iron core. The second scanning coil group is symmetrically arranged along a second horizontal direction perpendicular to the beam propagation direction, and is used to generate a second deflection magnetic field along the second horizontal direction to drive the particle beam to scan along the first horizontal direction. The second scanning coil group includes a first group of coils and a second group of coils, wherein the second group of coils is used to optimize the excitation efficiency of the iron core; The first horizontal direction and the second horizontal direction are orthogonal to each other.

2. The integrated scanning magnet according to claim 1, characterized in that, The iron core adopts a window frame structure, and the left half of the iron core and the right half of the iron core symmetrically form a closed magnetic circuit.

3. The integrated scanning magnet according to claim 1, characterized in that, The end plate of the iron core is connected to the iron core body by slots. The slots are arranged in a preset shape to reduce the eddy currents generated by the end magnetic field at a fast scanning frequency and reduce the temperature rise of the iron core.

4. The integrated scanning magnet according to any one of claims 1 to 3, characterized in that, Also includes: A three-dimensional adjustable base is fixed to the bottom of the iron core for connection with the rotating frame and supports fine adjustment in the X, Y, and Z directions to calibrate the positional deviation between the magnet center and the beam center.

5. The integrated scanning magnet according to any one of claims 1 to 3, characterized in that, Also includes: The water distributor is installed on the upper and lower bottom surfaces of the iron core and is used to evenly distribute the cooling medium of the external cooling system to the first scanning coil and the second scanning coil group.

6. The integrated scanning magnet according to claim 1, characterized in that, The shape and position of the first and second scanning coil groups were optimized through three-dimensional magnetic field calculations, so that the magnetic field uniformity within the good field area reached ±5×10⁻⁶. -3 .

7. The integrated scanning magnet according to claim 1, characterized in that, Both the first scanning coil and the second scanning coil group are made of hollow wire with an outer square and an inner circle, and the hollow wire is filled with a cooling medium.

8. The integrated scanning magnet according to claim 1, characterized in that, The core is made of high-permeability silicon steel sheets laminated together. The high-permeability silicon steel sheets are 0.35 mm thick and are made of cold-rolled non-oriented silicon steel sheets.

9. The integrated scanning magnet according to claim 1, characterized in that, The iron core is cast separately from the first scanning coil and the second scanning coil to facilitate individual replacement of the iron core or coil.

10. A proton and heavy ion therapy device, characterized in that, include: Rotating frame; The integrated scanning magnet as described in any one of claims 1 to 9 is mounted on the rotating frame and is used to control the deflection direction of the beam.

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