Magnetic confinement fusion device and method for optimizing the same

Abstract

The application discloses a magnetic confinement fusion device, comprising a vacuum chamber, a dipole field coil system, a plurality of toroidal field coils and a plasma region, wherein the vacuum chamber is used for containing plasma; the dipole field coil system comprises a plurality of dipole field coils, each of which is installed outside the vacuum chamber and arranged around the vacuum chamber to provide a poloidal magnetic field for confining the plasma; the plurality of toroidal field coils are arranged outside the vacuum chamber and the dipole field coil system along the toroidal direction of the vacuum chamber to provide a toroidal magnetic field for confining the plasma, and the plurality of toroidal field coils and the dipole field coil system jointly form a closed toroidal magnetic surface; and the plasma region is located in the closed toroidal magnetic surface. The application generates various different magnetic fields by relatively simple dipole field coils and toroidal field coils to confine the plasma, and is convenient to construct.

Description

Technical Field

[0001] This invention belongs to the field of magnetic confinement fusion technology, specifically relating to a magnetic confinement fusion device and its optimization method. Background Technology

[0002] In the field of magnetic confinement fusion, stellarators are important plasma confinement devices. Their core objective is to confine high-temperature plasma through complex three-dimensional magnetic field configurations, ultimately serving as reaction vessels for plasma fusion. Traditional stellarator designs rely on complex three-dimensional modular coils to generate the required magnetic field configurations; however, this design faces numerous challenges in terms of engineering implementation and economics. The following section will cite the background technology closest to this invention and objectively analyze its problems and causes.

[0003] D. Williamson et al. proposed a scheme to replace traditional three-dimensional modular coils with saddle coils for the NCSX configuration. They attempted to simplify the coil structure and generate the desired magnetic field configuration by cutting the saddle coils using a surface current method (Paper 1: D. Williamson et al., Design description of the saddle coils for the National Compact Stellarator Experiment (NCSX), in the Proceedings of the 18th IEEE / NPSS Fusion Engineering Workshop, Albuquerque, New Mexico, 1999, pp. 441-444). This scheme relies on a complex optimization process. Although the saddle coils completely replace the three-dimensional modular coils, their design and manufacturing still require high precision, and the engineering difficulty is not fundamentally reduced. Furthermore, this design is optimized for a specific configuration, making it difficult to switch between multiple magnetic field configurations by adjusting coil parameters, thus limiting the experimental flexibility of the device.

[0004] TS Pedersen et al. designed and constructed a CNT device using four circular planar coils to study the confinement of non-neutral plasmas (Paper 2: TS Pedersen et al., Confinement of Non-neutral Plasmas on Magnetic Surfaces, Physical Review Letters, 2002, Vol. 88, p. 205002). This design is primarily for non-neutral plasmas and cannot be directly applied to high-temperature plasma confinement, which is inconsistent with the needs of stellarator fusion research. While the circular planar coil structure is simple, it is difficult to generate quasi-symmetric magnetic field configurations for stellarators, limiting its application in complex magnetic field optimization. The fixed coil design, with the only possible switching of magnetic field configurations by changing the angle between the crossed coils, has a very limited range of variability, making it difficult to meet the requirements for magnetic field flexibility.

[0005] LP Ku et al. proposed using a windowed coil combined with a surface current method to simplify the shape of three-dimensional modular coils, thereby generating quasi-axisymmetric stellarator magnetic field configurations (Paper 3: LP Ku et al., Modularcoils and plasma configurations for quasi-axisymmetric stellarators, published in Nucl. Fusion, 2010, Vol. 50, p. 125005). This approach is mainly designed for fixed magnetic field configurations and cannot achieve flexible switching between multiple magnetic field configurations within a single device, thus limiting the diversity of experimental research.

[0006] P. Helander et al. proposed using permanent magnets to replace three-dimensional coils, simplifying the coil structure of stellarators and reducing the difficulty and cost of stellarator construction (Paper 4: P. Helander et al., "Stellarators with Permanent Magnets", Physical Review Letters, 2020, Vol. 124, p. 095001). However, the magnetic field strength of permanent magnets is limited and difficult to adjust, and their stability in high-temperature and high-radiation environments is questionable, failing to meet the high precision requirements of magnetic fields and hindering their widespread application in fusion devices. Furthermore, once fixed, permanent magnets cannot dynamically adjust the magnetic field configuration, making it impossible to achieve multiple magnetic field configurations.

[0007] SA Henneberg et al. designed a tokamak-stellar hybrid configuration by adding a saddle-shaped coil inside the small loop instead of a modular three-dimensional coil (Paper 5: SA Henneberg et al., "Compact stellarator-tokamakhybrid", Physical Review Research, Vol. 6, p. L022052). This design was optimized for the hybrid configuration, and although it simplified the coil structure, it failed to achieve flexible switching between various quasi-symmetric magnetic field configurations. Summary of the Invention

[0008] The purpose of this invention is to provide a magnetic confinement fusion device and its optimization method to solve the problems of complex three-dimensional modular coil systems in traditional stellarator devices, which lead to high engineering construction difficulty and cost, as well as the difficulty in realizing multiple stellarator magnetic field configurations in a single device.

[0009] To achieve the above objectives, the present invention provides a magnetic confinement fusion device, comprising: a vacuum chamber having a closed annular structure, the vacuum chamber being used to contain plasma; a dipole field coil system including a plurality of dipole field coils, all of which are installed outside the vacuum chamber and arranged around the vacuum chamber to provide a poloidal magnetic field for confining the plasma; a plurality of circumferential field coils surrounding the vacuum chamber and the dipole field coil system and arranged at circumferential intervals along the vacuum chamber to provide a circumferential magnetic field for confining the plasma, the plurality of circumferential field coils and the dipole field coil system together forming a closed annular magnetic surface; and a plasma region located within the closed annular magnetic surface.

[0010] Preferably, the vacuum chamber has a circumferentially symmetrical structure.

[0011] Preferably, the number of the circumferential field coils is greater than or equal to 2 and less than or equal to 200.

[0012] Preferably, the outer wall of the vacuum chamber is provided with a support structure corresponding to the dipole field coil system to fix the dipole field coil.

[0013] Preferably, the number of dipole field coils in the dipole field coil system is greater than or equal to 2 and less than or equal to 100,000.

[0014] Preferably, it further includes a controller for controlling the current in the dipole field coil and the circumferential field coil.

[0015] Preferably, it further includes a central solenoid coil and several poloidal field coils. The central solenoid coil is located at the center of the vacuum chamber, and the poloidal field coils are arranged circumferentially around the outside of the vacuum chamber. The poloidal field coils, the central solenoid coil, and the circumferential field coils form a tokamak structure.

[0016] The present invention also provides an optimization method for a magnetic confinement fusion device, including the aforementioned magnetic confinement fusion device. The optimization method includes the following steps: S110, determining the arrangement of the dipole field coil system and the circumferential field coil; S120, initializing the plasma boundary shape; S130, keeping the shape and position of the dipole field coil system and the circumferential field coil unchanged, and setting the current of the dipole field coil, the current of the circumferential field coil, and the plasma boundary shape as optimizable degrees of freedom; S140, defining the objective optimization function; S150, using an optimization algorithm to iteratively calculate the objective optimization function until each objective function reaches a predetermined value.

[0017] Preferably, the objective optimization function includes, but is not limited to, plasma boundary shape, plasma boundary magnetic field normal residual component, plasma transport coefficient, and magnetic field rotation transformation.

[0018] Preferably, the constraints of the optimization algorithm include: the total normal magnetic field component generated by the dipole field coil system, the circumferential field coil, and the plasma current on the plasma boundary surface is less than a first preset value to ensure magnetic surface closure; and the current value of the dipole field coil in the dipole field coil system is less than a second preset value, and the current value in the circumferential field coil is less than a third preset value.

[0019] Compared with the prior art, the present invention sets up a dipole field coil system and several circumferential field coils, and makes the circumferential field coils and the dipole field coil system together form a closed ring magnetic surface. This allows the present invention to generate various magnetic fields to confine plasma using relatively simple dipole field coils and circumferential field coils, which is convenient for construction. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the first structure of the magnetic confinement fusion device according to an embodiment of the present invention.

[0021] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure of the medium vacuum chamber and the dipole field coil system.

[0022] Figure 3 for Figure 1 A top view of the medium vacuum chamber and the dipole field coil system.

[0023] Figure 4This is a schematic diagram of a second structure of the magnetic confinement fusion device according to an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached diagram: 1. Vacuum chamber; 2. Dipole field coil system; 21. Dipole field coil; 3. Circular field coil; 4. Plasma region; 5. Central solenoid coil; 6. Pole field coil. Detailed Implementation

[0025] To illustrate the technical content, structural features, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0026] like Figures 1 to 4 As shown, this embodiment of the invention provides a magnetic confinement fusion device, including a vacuum chamber 1, a dipole field coil system 2, a plurality of circumferential field coils 3, and a plasma region 4. The vacuum chamber 1 has a closed ring structure and is used to contain plasma. The dipole field coil system 2 includes a plurality of dipole field coils 21, which are all installed outside the vacuum chamber 1 and arranged around the vacuum chamber 1 to provide a poloidal magnetic field for confining the plasma. The plurality of circumferential field coils 3 are arranged around the vacuum chamber 1 and the dipole field coil system 2 and are spaced circumferentially around the vacuum chamber 1 to provide a circumferential magnetic field for confining the plasma. The plurality of circumferential field coils 3 and the dipole field coil system 2 together form a closed ring magnetic surface, and the plasma region 4 is located in the closed ring magnetic surface. Specifically, as shown... Figures 1 to 3 As shown, the magnetic confinement fusion device in this embodiment of the invention is specifically a stellarator structure. The vacuum chamber 1 is placed horizontally, and the material of the vacuum chamber 1 can be selected according to actual needs, such as high-strength stainless steel. The dipole field coil 21 can be made of any conductive material, such as copper wire, low-temperature superconducting material, high-temperature superconducting material, etc. The dipole field coil 21 is installed outside the vacuum chamber 1, which facilitates the fabrication and installation of the dipole field coil 21. The shape of the dipole field coil 21 can be any suitable geometric shape, including but not limited to saddle shape, circle, ellipse, rectangle, or other planar or non-planar shapes. The circumferential field coil 3 can be a planar coil of any shape, such as a circular planar coil, D-shaped planar coil, etc. Several circumferential field coils 3 are placed around the vacuum chamber 1 to provide the circumferential magnetic field required by the magnetic confinement fusion device.

[0027] In this embodiment of the invention, by setting up a dipole field coil system 2 and several circumferential field coils 3, and making the circumferential field coils 3 and the dipole field coil system 2 together form a closed annular magnetic surface, the magnetic confinement fusion device of this embodiment of the invention can generate various different magnetic fields to confine plasma using relatively simple dipole field coils 21 and circumferential field coils 3, which is convenient for construction.

[0028] In this embodiment of the invention, the vacuum chamber 1 has a circumferentially symmetrical structure. Specifically, as shown... Figures 1 to 2As shown, vacuum chamber 1 is specifically a ring structure. The cross-section of vacuum chamber 1 can be circular, and the radius of the cross-section of vacuum chamber 1 is the smaller radius r. The distance between the central axis Z of vacuum chamber 1 and the annular inner axis of the inner cavity of vacuum chamber 1 is the larger radius R. The ratio of the larger radius R to the smaller radius r of vacuum chamber 1 can be greater than or equal to 1.1 and less than or equal to 100. The ratio of the larger radius R to the smaller radius r of vacuum chamber 1 is preferably 2. Vacuum chamber 1 does not come into contact with the plasma inside. By setting vacuum chamber 1 as a ring-symmetric structure with a circular cross-section, it is easier to manufacture vacuum chamber 1. In some other specific embodiments, the cross-section of vacuum chamber 1 can also be elliptical or other structures. There are no restrictions here, as long as the structure of vacuum chamber 1 can ensure that it does not come into contact with the plasma.

[0029] In this embodiment of the invention, the number of dipole field coils 21 in the dipole field coil system 2 is greater than or equal to 2 and less than or equal to 100,000. Specifically, for example... Figure 1 As shown, the dipole field coil 21 is saddle-shaped, but the present invention does not limit the specific shape, reflecting the flexibility of the dipole field coil 21. Figures 1 to 3 As shown, several dipole field coils 21 form multiple sets of coil units. Each set of coil units corresponds to the same circumferential angle, and each dipole field coil 21 within each set of coil units corresponds to the same poloidal angle. For example, as... Figures 1 to 3 As shown, several dipole field coils 21 are uniformly arranged around the vacuum chamber 11 with equal circumferential and equal pole angles. The dipole field coil system 2 includes 24 groups of coil units uniformly arranged with equal circumferential angles in the circumferential direction. The circumferential angle corresponding to each group of coil units is 15 degrees. Each group of coil units includes 12 dipole field coils 21 uniformly arranged with equal pole angles in the pole direction. The pole angle corresponding to each dipole field coil 21 in each group of coil units is 30 degrees, thus forming a total of 288 dipole field coils 21. The size of the dipole field coil 21 is determined by the size of the corresponding toroidal surface, as well as the circumferential and pole coordinates. The dipole field coils 21 on the side closer to the central axis Z of the vacuum chamber 1 have the smallest size, and the coils on the side farther from the central axis Z of the vacuum chamber 1 have the largest size, as detailed below. Figures 1 to 3 As shown, Figure 2 The arrangement of the dipole field coil system 2 in the circumferential direction (0-π range) is shown, highlighting the variation of the size of the dipole field coil 21 with the polar angle θ, and the uniform distribution of the dipole field coil 21 along the circumferential direction. Figure 3A top view of the dipole field coil system 2 is shown, illustrating its arrangement in the circumferential direction (0-π range) and the layout of the dipole field coils 21 within the circumferential angle φ. The diagram highlights the variation in coil size with position: the dipole field coils 21 closest to the central axis Z of the vacuum chamber 1 are the smallest, while those furthest from the central axis Z are the largest. The dipole field coils 21 are symmetrically arranged in the circumferential direction, and those with the same polar angle have the same shape and size in the circumferential direction. Of course, in some other embodiments, the circumferential angles corresponding to multiple sets of coil units can be different. For example, one set of coil units may have a circumferential angle of 15 degrees, while another set may have 14 or 16 degrees. Therefore, the circumferential angle corresponding to each set of coil units can be set according to actual needs. Furthermore, in other embodiments, multiple sets of coil units may have the same circumferential angle, but the polar angles corresponding to the dipole field coils 21 within each set may be different.

[0030] In this embodiment of the invention, the number of toroidal field coils 3 is greater than or equal to 2 and less than or equal to 200. Specifically, the toroidal field coils 3 can be circular planar coils. The toroidal field coils 3 are placed vertically around the vacuum chamber 11, and any two adjacent toroidal field coils 3 form the same toroidal angle. The toroidal field coils 3 provide the toroidal magnetic field required by the magnetic confinement fusion device and together with the dipole field coil system 2, form a closed magnetic surface. The number of toroidal field coils 3 can be adjusted according to requirements, such as... Figure 1 As shown in the embodiment of the present invention, the number of circumferential field coils 3 is 12. The 12 circumferential field coils 3 are evenly distributed in the circumferential direction. It should be noted that the number of circumferential field coils 3 can be selected according to actual needs, and the shape of the circumferential field coils 3 can also be other shapes, such as D-shaped planar coils.

[0031] In this embodiment of the invention, a support structure is provided on the outer wall of the vacuum chamber 1 corresponding to the dipole field coil system 2 to fix the dipole field coil 21. Specifically, the support structure can be a support frame, which is arranged around the vacuum chamber 1 and can be installed on the vacuum chamber 1. The support frame does not need to be completely attached to the vacuum chamber 1. Several frame units are set on the support frame corresponding to several dipole field coils 21, and each frame unit is used to install one dipole field coil 21.

[0032] In this embodiment of the invention, the magnetic confinement fusion device further includes a controller for controlling the current in the dipole field coil 21 and the toroidal field coil 3. Specifically, each dipole field coil 21 and each toroidal field coil 3 is independently powered by a power system, and the current magnitude of each dipole field coil 21 and each toroidal field coil 3 is adjusted by the controller to achieve switching between different magnetic field configurations. Of course, in some other specific embodiments, the dipole field coil 21 and the toroidal field coil 3 may not be independently powered, but rather two or more dipole field coils 21 may share a power supply unit in the power system, or two or more toroidal field coils 3 may share another power supply unit in the power system. In addition, the magnetic confinement fusion device also includes plasma heating equipment, diagnostic equipment, divertors, blankets, Dewars, and other equipment and structures. These structures are conventional structures of magnetic confinement fusion devices and will not be described in detail here.

[0033] like Figure 4 As shown, in some other specific embodiments of the present invention, the magnetic confinement fusion device further includes a central solenoid coil 5 and several poloidal field coils 6. The central solenoid coil 5 is located at the center of the vacuum chamber 1, and the poloidal field coils 6 are arranged circumferentially around the outside of the vacuum chamber 1. The poloidal field coils 6, the central solenoid coil 5, and the circumferential field coils 3 form a tokamak structure. Specifically, the circumferential field coil 3 is a D-shaped planar coil, which is placed vertically around the vacuum chamber 11. Any two adjacent circumferential field coils 3 form the same circumferential angle. The poloidal field coil 6 has a circular ring structure. The structure of the vacuum chamber 1 can be selected according to actual needs. Preferably, the vacuum chamber 1 with a circular cross-section and a circumferentially symmetrical structure is selected. When the magnetic confinement fusion device is switched to a tokamak structure, no current is passed through the dipole field coil system 2 or the current passed through it is very small. The central solenoid coil 5, the poloidal field coil 6 and the circumferential field coil 3 work together to form a closed ring magnetic surface to confine the plasma motion. When the tokamak structure is switched to a stellarator structure, no current is passed through the central solenoid coil 5 and the poloidal field coil 6. Only the dipole field coil system 2 and the circumferential field coil 3 pass through the current to form a closed ring magnetic surface. The magnetic confinement fusion device of this embodiment can be applied not only to stellarator structures but also to tokamak structures, with a wider range of applications and a very ingenious design. In addition, it should be noted that the central solenoid coil 5, the poloidal field coil 6, and the circumferential field coil 3 can work together to form a magnetically confined configuration with anti-field clamping, thereby further expanding the applicability of the embodiments of the present invention.

[0034] In this embodiment of the invention, the dipole field coil system 2 has the following key characteristics and functions: 1. Magnetic Field Generation: The dipole field coil system 2 provides a poloidal magnetic field, which, together with the toroidal field coil 3, generates a closed toroidal magnetic surface structure. The outermost magnetic surface of the toroidal magnetic surface structure does not intersect with the inner wall of the vacuum chamber 1. 2. Magnetic Field Configuration Flexibility: By adjusting the current ratio of the dipole field coil 21, various quasi-symmetric magnetic field configurations can be generated, including quasi-axial symmetry, quasi-spiral symmetry, and quasi-line force symmetry. The periodicity of the magnetic field configuration is determined by the periodicity of the current arrangement of the dipole field coil 21. 3. Symmetry Adjustment: The accuracy of the magnetic field symmetry is achieved through optimized adjustment of the currents of the dipole field coil 21 and the poloidal field coil 6. Specific symmetries can be retained or discarded according to experimental requirements. 4. Coil Shape Flexibility: The shape of the dipole field coil 21 is not limited to a specific geometric form. Any suitable shape can be selected according to design requirements to optimize magnetic field generation efficiency and engineering feasibility.

[0035] Traditional three-dimensional modular coils require complex geometric design and high-precision machining, resulting in high manufacturing costs and sensitivity to installation errors. This invention simplifies the geometry of the dipole field coil 21 by using arbitrarily shaped dipole field coils 21, such as saddle-shaped, circular, elliptical, and rectangular coils, allowing for standardized machining processes. The symmetrical arrangement of the dipole field coils 21 (uniform distribution in the circumferential and polar directions) further reduces installation accuracy requirements and minimizes the need for additional auxiliary coils or adjustment devices for error correction. Furthermore, this invention allows for flexible switching between multiple quasi-symmetric magnetic field configurations (such as quasi-axisymmetric, quasi-spiraly, and quasi-force lineymmetric) within a single device by independently controlling the current ratio of each dipole field coil 21, significantly improving the experimental flexibility and application value of the device. By using the coil current as an optimization variable, combined with the optimization method for magnetic confinement fusion devices described below, this invention can rapidly generate magnetic field configurations with different symmetries. The controller precisely controls the current with a control accuracy of ±0.1%, ensuring the switching speed and accuracy of the magnetic field configuration. The flexibility of the dipole field coil 21 shape (arbitrary geometry) allows for optimization of the coil arrangement according to experimental requirements, further enhancing the adaptability of magnetic field generation. The magnetic confinement fusion device of this invention is suitable for high-temperature plasma experiments, and can be used to study quasi-axisymmetric, quasi-spiral symmetric, and quasi-isodynamic magnetic field configurations. It can also be used for fusion energy development and plasma physics research.

[0036] To achieve high-precision magnetic field configuration and reduce engineering construction difficulty, this invention also provides an optimization method for a magnetic confinement fusion device, including the aforementioned magnetic confinement fusion device. The optimization method includes the following steps: S110, determine the arrangement of the dipole field coil system 2 and the toroidal field coil 3; specifically, determine the arrangement of the dipole field coil system 2 and the toroidal field coil 3. The size, quantity, and shape of the dipole field coil 21 and the toroidal field coil 3 are set according to design requirements, for example, such as... Figures 1 to 3As shown, the dipole field coil system 2 includes 24 groups of coil units evenly arranged at equal circumferential angles in the circumferential direction. Each group of coil units includes 12 dipole field coils 21 evenly arranged at equal pole angles in the polar direction, for a total of 288 dipole field coils 21. The number of circumferential field coils 3 is 12 evenly arranged in the circumferential direction.

[0037] S120, Initialize the plasma boundary shape. Specifically, a ring structure with a circular cross-section can be selected as the initial optimized configuration of the plasma boundary shape. It should be noted that the plasma boundary shape can be adjusted according to requirements. For example, based on known information, starting from certain specific shapes may lead to easier convergence, and such specific shapes can be selected as the initial optimized configuration of the plasma boundary shape.

[0038] S130, keeping the shape and position of the dipole field coil system 2 and the circumferential field coil 3 unchanged, the current of the dipole field coil 21, the current of the circumferential field coil 3, and the shape of the plasma boundary are set as optimizable degrees of freedom.

[0039] S140, Define the objective optimization function. Specifically, the objective optimization function includes, but is not limited to, plasma boundary shape, plasma boundary magnetic field normal residual component, plasma transport coefficient, and magnetic field rotation transformation. The specific formula for the objective optimization function is as follows: , in Let the overall objective function be , To optimize the independent variable, namely the plasma boundary shape; For the first An optimization objective function, Its corresponding optimization weight; This refers to the normal residual component of the plasma boundary magnetic field; Let be the plasma boundary magnetic field distribution function, for example, This represents the quasi-symmetric asymmetric component of the plasma boundary magnetic field; and These are magnetic field rotation transformation and toroidal diameter ratio, respectively.

[0040] S150 uses an optimization algorithm to iteratively calculate the objective optimization function until each objective function reaches a predetermined value, which is greater than or equal to 0.0001 and less than or equal to 0.01. The optimization algorithm can be a nonlinear optimization algorithm, including but not limited to gradient descent, difference evolution, and genetic algorithm.

[0041] In this embodiment of the invention, the constraints of the optimization algorithm include: The normal component of the total magnetic field generated by the dipole field coil system 2, the circumferential field coil 3, and the plasma current on the plasma boundary surface is less than a first preset value to ensure magnetic surface closure; and the current value of the dipole field coil 21 in the dipole field coil system 2 is less than a second preset value, and the current value in the circumferential field coil 3 is less than a third preset value. Specifically, the first preset value should be as close to 0 as possible. The specific values ​​of the first, second, and third preset values ​​can be selected and set according to actual needs. Other design parameters such as magnetic field rotation transformation and toroidal diameter ratio are set according to experimental requirements. The quasi-symmetric asymmetric component of the plasma boundary magnetic field needs to be minimized to improve symmetry accuracy.

[0042] Furthermore, the process conditions for optimizing the magnetic confinement fusion device include: The optimization process needs to be executed on a high-performance computing platform, such as a computer with 32 cores and 128GB of memory, to ensure rapid iteration and convergence. The number of iterations depends on the complexity of the objective function, and convergence usually requires hundreds to thousands of iterations. During the optimization process, it is necessary to ensure that the plasma boundary magnetic surface is closed and does not intersect with the inner wall of vacuum chamber 1.

[0043] The core advantages of the optimization method for the magnetic confinement fusion device in this invention are: by using the current of the dipole field coil 21, the current of the circumferential field coil 3, and the plasma boundary shape as common optimization variables, the magnetic field and coils are optimized synchronously, overcoming the problem of magnetic field and coil mismatch in the traditional "two-step" optimization; the optimization method supports the generation of various magnetic field configurations, adapts to different experimental needs, and is highly flexible; and through nonlinear optimization algorithms, the stability of the optimization results under different design parameters is ensured, exhibiting good robustness.

[0044] The optimization method for magnetic confinement fusion devices in this invention significantly improves the quasi-symmetry accuracy and optimization robustness of the magnetic field configuration by simultaneously optimizing the coil current and plasma boundary shape, reducing the mismatch between the magnetic field and the coil, and ensuring plasma confinement performance. Traditional two-step optimization methods often suffer from mismatch in the second step of coil design due to limited solution space after the first step of magnetic field optimization, resulting in high quasi-symmetry and asymmetric components of the magnetic field. This invention uses the coil current and plasma boundary shape as common optimization variables, minimizing the normal magnetic field component and the quasi-symmetry and asymmetric components through a nonlinear optimization algorithm, significantly improving the magnetic field accuracy. The robustness of the optimization algorithm benefits from high-performance computing support and reasonable initial conditions (such as the circular cross-section boundary shape), ensuring the stability of the optimization results under different design parameters.

[0045] The following describes a specific implementation of a magnetic confinement fusion device, wherein: Vacuum chamber 1 has a circular polar cross-section with a circumferentially symmetrical structure. The large radius of vacuum chamber 1 is R=2m, and the small radius is r=1m. The ring diameter ratio of vacuum chamber 1 is R / r=2. Vacuum chamber 1 is made of high-strength stainless steel, such as 316L, to ensure corrosion resistance and vacuum sealing in high-temperature plasma environments. Vacuum chamber 1 is manufactured by precision CNC machining to ensure that the cross-sectional accuracy of vacuum chamber 1 reaches ±0.1mm. The inner wall of vacuum chamber 1 may have cladding or other auxiliary structures. Vacuum chamber 1 is polished after welding. The dipole field coil system 2 is shaped like a saddle-shaped coil, with several dipole field coils 21 evenly arranged along the circumferential and polar directions, such as... Figures 1 to 3 As shown, there are 288 dipole field coils 21. The size of the dipole field coils 21 is determined by the coordinates of the corresponding toroidal surface. The dipole field coils 21 closer to the central axis Z of the vacuum chamber 1 have the smallest size, and the dipole field coils 21 farther from the central axis Z of the vacuum chamber 1 have the largest size. The material of the dipole field coils 21 is a high-temperature superconducting material, such as ReBCO. The operating temperature of the high-temperature superconducting material is 10~77K, and the current density of the high-temperature superconducting material reaches 100A / mm². The coil frame of the dipole field coils 21 is formed by machine tool processing or 3D printing technology. The superconducting tape is wound by a winding machine. After the coil is wound, it is tested at low temperature to ensure the superconducting performance. The dipole field coils 21 are fixed on the support structure on the outer wall of the vacuum chamber 1. The support frame of the support structure is made of non-magnetic stainless steel, which makes the spacing of the dipole field coils 21 uniform. The toroidal field coil 3 is in the shape of a circular planar coil or a D-shaped planar coil. The number of toroidal field coils 3 can be greater than or equal to 4 and less than or equal to 100. The toroidal field coils 3 are placed vertically and uniformly along the circumferential direction. The radius of the toroidal field coil 3 is about 1.6m, and the cross-sectional width of the toroidal field coil 3 is 0.1m. The material of the toroidal field coil 3 is a conventional conductor or a superconducting material. The toroidal field coil 3 is manufactured by a standard winding process and is fixedly installed around the vacuum chamber 1. After the toroidal field coil 3 is wound, it undergoes low-temperature testing to ensure superconducting performance. Plasma region 4 forms a closed annular magnetic surface, with the outermost magnetic surface at least 0.1m away from the inner wall of vacuum chamber 1; The magnetic field strength is preferably greater than or equal to 1T and less than or equal to 2T, and the perpendicular component of the magnetic field is less than 0.1%. The power supply system ensures that each dipole field coil 21 and each circumferential field coil 3 are independently powered, with a current range greater than or equal to 0 and less than or equal to 100kA, and a current control accuracy of ±0.1%; the power supply system adopts a high-precision DC power supply and is equipped with a real-time controller. The method of using the magnetic confinement fusion device in this embodiment of the invention is as follows: First, start the vacuum system and ensure that the pressure in vacuum chamber 1 is <10. -6Pa, cool the coil to 77K, start the power system, input the optimized current ratio, generate a specific three-dimensional magnetic field, inject plasma, and conduct a confinement experiment.

[0046] The magnetic confinement fusion device of this invention is used for high-temperature plasma experiments, fusion energy research, and plasma physics experiments, and can be extended to small and medium-sized experimental devices or large fusion reactors.

[0047] The magnetic confinement fusion device of this invention is also equipped with testing equipment such as a vacuum pump and a magnetic field measuring instrument. The above-disclosed examples are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention shall still fall within the scope of the present invention.

Claims

1. A magnetic confinement fusion device, characterized in that, include: A vacuum chamber, having a closed ring structure, is used to contain plasma; A dipole field coil system includes a plurality of dipole field coils, all of which are mounted outside the vacuum chamber and arranged around the vacuum chamber to provide a poloidal magnetic field to confine the plasma. A plurality of circumferential field coils are arranged around the vacuum chamber and the outside of the dipole field coil system and at circumferential intervals along the vacuum chamber to provide a circumferential magnetic field to confine the plasma. The plurality of circumferential field coils and the dipole field coil system together form a closed annular magnetic surface. The plasma region is located within the closed annular magnetic surface.

2. The magnetic confinement fusion device according to claim 1, characterized in that, The vacuum chamber has a circumferentially symmetrical structure.

3. The magnetic confinement fusion device according to claim 1, characterized in that, The number of the circumferential field coils is greater than or equal to 2 and less than or equal to 200.

4. The magnetic confinement fusion device according to claim 1, characterized in that, The outer wall of the vacuum chamber is provided with a support structure corresponding to the dipole field coil system to fix the dipole field coil.

5. The magnetic confinement fusion device according to claim 1, characterized in that, The number of dipole field coils in the dipole field coil system is greater than or equal to 2 and less than or equal to 100,000.

6. The magnetic confinement fusion device according to claim 1, characterized in that, It also includes a controller for controlling the current in the dipole field coil and the circumferential field coil.

7. The magnetic confinement fusion device according to claim 1, characterized in that, It also includes a central solenoid coil and several poloidal field coils. The central solenoid coil is located at the center of the vacuum chamber, and the poloidal field coils are arranged circumferentially around the outside of the vacuum chamber. The poloidal field coils, the central solenoid coils, and the circumferential field coils form a tokamak structure.

8. An optimization method for a magnetic confinement fusion device, characterized in that, The optimization method, comprising the magnetic confinement fusion device as described in any one of claims 1 to 6, includes the following steps: S110, determine the arrangement of the dipole field coil system and the circumferential field coil; S120, Initialize plasma boundary shape; S130, keeping the shape and position of the dipole field coil system and the circumferential field coil unchanged, and setting the current of the dipole field coil, the current of the circumferential field coil, and the shape of the plasma boundary as optimizable degrees of freedom; S140, Define the objective optimization function; S150 uses an optimization algorithm to iteratively calculate the objective optimization function until each objective function reaches a predetermined value.

9. The optimization method for a magnetic confinement fusion device according to claim 8, characterized in that, The objective optimization function includes, but is not limited to, plasma boundary shape, plasma boundary magnetic field normal residual component, plasma transport coefficient, and magnetic field rotation transformation.

10. The optimization method for a magnetic confinement fusion device according to claim 8, characterized in that, The constraints of the optimization algorithm include: The total normal magnetic field component generated by the dipole field coil system, the circumferential field coil, and the plasma current on the plasma boundary surface is less than a first preset value to ensure magnetic surface closure; and the current value of the dipole field coil in the dipole field coil system is less than a second preset value, and the current value in the circumferential field coil is less than a third preset value.

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