CN114121400B - A Simplified Permanent Magnet Stellarator Device - Google Patents

Abstract

The invention provides a simplified permanent magnet star simulator device. The device adopts a rectangular polar section vacuum chamber to contain plasma, a rectangular planar coil which surrounds the vacuum chamber and is uniformly distributed in the circumferential direction generates a circumferential magnetic field required by the magnetic field position type of the star-like device, and a standardized permanent magnet module which is arranged outside the vacuum chamber and has the magnetization direction pointing to or deviating from the vacuum chamber generates a polar magnetic field required by the magnetic field position type of the star-like device. The invention greatly simplifies the complex coil system and the vacuum chamber structure of the star simulator device, and can remarkably reduce the construction difficulty and cost of the star simulator, so that the star simulator has excellent economical competitiveness and is very suitable for being used as a plasma experiment research device or providing a high-parameter plasma source for the application field of plasmas.

Description

A Simplified Permanent Magnet Stellarator Device

technical field

The invention belongs to the field of magnetic confinement fusion energy, relates to stellarator physics and engineering design, in particular to a simplified permanent magnet stellarator device.

Background technique

Stellarator is one of the most important types of research devices in the field of magnetic confinement fusion research, which confines plasma through a three-dimensional asymmetric magnetic field. However, precisely because of the asymmetrical characteristics of its magnetic field configuration, stellarators usually need to use very complicated three-dimensional twisted coils to generate the magnetic field. Manufacturing and assembling complex three-dimensional coils, especially superconducting coils, with sufficient precision is difficult and expensive. In addition, because the previous coil design program needs to design the coil on the surface of the vacuum chamber (winding surface), if the surface of the vacuum chamber is similar to the shape of the plasma boundary, it is easier to find a simple coil, which makes the shape and structure of the stellarator vacuum chamber very complicated. , so the difficulty and cost of its processing and manufacturing are also very high. Even though a program for coil design that does not depend on the curved surface of the vacuum chamber has been developed recently, the space for designing the vacuum chamber around it is still very limited due to the complex shape of the coil itself and its layout, so the design of the vacuum chamber is still limited. Big restrictions.

The latest research shows that permanent magnets combined with planar coils can replace three-dimensional twisted wire coils to generate the stellarator magnetic field pattern. The planar coils are used to generate the main toroidal magnetic field, and the permanent magnets are used to generate the poloidal magnetic field and part of the rotation transformation. Planar coils have a very mature and advanced manufacturing process, and their production difficulty and cost are much lower than those of complex three-dimensional twisted coils. Permanent magnets are cheap and do not require energy to maintain. Therefore, the design of permanent magnets combined with planar coils may greatly reduce the difficulty and cost of stellarator construction. The published patent CN202011636945.4 has proposed a standardized permanent magnet design based on this concept, which has laid a solid foundation for the engineering realization of permanent magnet stellarator. In addition, the free and flexible arrangement of the permanent magnets greatly increases the degree of freedom in the design of the stellarator, which provides the feasibility for the simplified design of the stellarator vacuum chamber. Recently, Princeton University in the United States is preparing to build a small permanent magnet stellarator device (MUSE), which uses a circular planar coil and a circular polar cross-section vacuum chamber, which simplifies the structure of the stellarator device to a certain extent. However, the distribution of the permanent magnets arranged outside the vacuum chamber and the corresponding magnet frame structure are relatively complicated, and it is difficult to control the assembly accuracy of the permanent magnets.

Since stellarators have many attractive advantages such as steady-state operation, no risk of rupture, and low recirculation energy, etc., a stellarator device with simple engineering and low cost will greatly promote the development of stellarator research, and , which can not only be used as a plasma experimental research device, but also provide a high-parameter plasma source for plasma applications.

Contents of the invention

Aiming at the characteristics of the stellarator coil system and the complex structure of the vacuum chamber, the present invention proposes a simplified permanent magnet stellarator device. The device uses a rectangular planar coil and a standardized permanent magnet module to generate the magnetic field configuration required by the stellarator. At the same time, it uses a vacuum chamber with a rectangular polar cross section, which greatly simplifies the structure of the stellarator vacuum chamber. This invention significantly reduces the structural complexity of the stellarator, and can greatly reduce the construction difficulty and cost of the stellarator.

A simplified permanent magnet stellarator device, including a rectangular poloidal cross-section vacuum chamber for containing plasma, a standardized permanent magnet module and a rectangular planar coil;

The vacuum chamber with a rectangular polar cross-section is a circumferentially symmetrical structure, the inner side (high field side) and the outer side (low field side) are curved, and the top and bottom are flat;

All the magnet blocks of the standardized permanent magnet module are cuboids of the same shape and size, and each magnet is uniformly magnetized along a direction perpendicular to its respective surface;

The standardized permanent magnet module is installed outside the vacuum chamber with rectangular polar cross-section, there is no vacancy inside each row of magnets and the magnetization direction of all magnet blocks in the same row is the same;

The magnetization direction of the standardized permanent magnet module points to or departs from the vacuum chamber with a rectangular polar cross section, wherein, at the top or bottom of the vacuum chamber with a rectangular polar cross section, the magnetization direction of the permanent magnet is vertical to the top or bottom plane upward or downward, On the inside or outside of the vacuum chamber with rectangular polar cross section, the magnetization direction of the permanent magnet at different circumferential positions is perpendicular to the tangent plane of the inner or outer curved surface of the vacuum chamber with rectangular polar cross section corresponding to the circumferential position inward or outward;

The rectangular planar coil is vertically placed around the rectangular poloidal section vacuum chamber and the standardized permanent magnet module.

Further, for each rectangular planar coil, there is a certain arc at its corner.

Further, the above-mentioned rectangular poloidal section vacuum chamber can replace the rectangular polar section with regular shapes such as pentagons, hexagons, heptagons, and octagons according to design requirements, and the magnetization direction can also be arranged at the corresponding positions A standardized permanent magnet module pointing or facing away from the vacuum chamber.

Further, the shape of the magnet block of the above-mentioned standardized permanent magnet module can also be replaced with other regular shapes, including: parallelogram prism, triangular prism, trapezoidal prism, etc. These shapes can be obtained by splitting and combining regular cuboid shapes.

Further, the remanence strength of all the magnet blocks of the above-mentioned standardized permanent magnet module can be all the same, but the magnet blocks at different positions can also choose different remanence strength according to requirements.

Further, the device also includes a poloidal field coil system, the poloidal field coil system includes a central solenoid and a balance field coil; the center solenoid is arranged in the center of the device; the balance field coil has One or more are arranged on the periphery of the device.

Further, the above-mentioned permanent magnet stellarator device can choose whether to use an auxiliary system such as the above-mentioned poloidal field coil system for plasma breakdown, heating and position control according to requirements.

The beneficial effects of the present invention are:

(1) The present invention adopts a vacuum chamber with a rectangular polar cross-section, which greatly simplifies the complex vacuum chamber structure of the existing stellarator, and the production and processing difficulty and cost are relatively low. In addition, the vacuum chamber with regular shape and polar cross-section is very beneficial to the arrangement of permanent magnets.

(2) According to the structural characteristics of the rectangular polar section vacuum chamber, a simple and standardized permanent magnet module arrangement method is proposed. This arrangement method has less degrees of freedom in the installation of permanent magnet blocks. On the one hand, it can significantly reduce the difficulty of magnet assembly accuracy control. On the other hand, it also reduces the difficulty and cost of subsequent device maintenance.

(3) The use of rectangular planar coils greatly simplifies the complex three-dimensional twisted coil system of existing stellarators. As one of the most important systems of the stellarator device, the simplification of the coil system can greatly reduce the difficulty and cost of stellarator construction.

(4) The combination of a rectangular poloidal cross-section vacuum chamber and a rectangular planar coil can leave a large space on the high field side for the arrangement of other structures, such as the poloidal direction for plasma breakdown, heating and position type control field coil system.

Description of drawings

Fig. 1 is a kind of simplified permanent magnet stellarator device of the present invention:

(1) Rectangular polar cross section vacuum chamber, (2) Standardized permanent magnet module, (3) Rectangular planar coil, (4) Plasma. Only half of the rectangular poloidal section vacuum chamber (1), standardized permanent magnet modules (2) and rectangular planar coils (3) are shown here.

Fig. 2 is a schematic diagram of grid division of the standardized permanent magnet module according to the present invention, in which only the inner permanent magnet grid in the circumferential direction (0, π/6) is shown.

Fig. 3 is a top view of the grid division of the standardized permanent magnet module in the circumferential direction (0, π/6) shown in Fig. 2 .

Fig. 4 has increased the simplified permanent magnet stellarator device of poloidal field coil system for the present invention:

(1) Rectangular polar cross-section vacuum chamber, (2) Standardized permanent magnet module, (3) Rectangular planar coil, (4) Plasma, (5) Central solenoid, (6) Balanced field coil. Only half of the rectangular poloidal section vacuum chamber (1), standardized permanent magnet modules (2) and rectangular planar coils (3) are shown here.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

According to an embodiment of the present invention, as shown in Fig. 1, propose a kind of simplified permanent magnet stellarator device, comprise the vacuum chamber (1) that is used to accommodate plasma (4) rectangular polar section, standardized permanent magnet module ( 2) and rectangular planar coil (3);

The vacuum chamber (1) with a rectangular polar cross-section is a circumferentially symmetrical structure, the inner side (high field side) and the outer side (low field side) are curved, and the top and bottom are flat;

All magnet blocks of the standardized permanent magnet module (2) are cuboids of the same shape and size, and each magnet is uniformly magnetized along a direction perpendicular to its respective surface, and all magnet blocks have the same residual magnetism;

The standardized permanent magnet module (2) is installed outside the vacuum chamber (1) with a rectangular polar cross section, there is no vacancy inside each row of magnets composed of magnet blocks, and the magnetization directions of all magnet blocks in the same row are the same;

The magnetization direction of the standardized permanent magnet module (2) points to or departs from the vacuum chamber (1) with a rectangular polar cross section, wherein, at the top or bottom of the vacuum chamber (1) with a rectangular polar cross section, the magnetization direction of the permanent magnet is perpendicular to The top or bottom plane is upward or downward, and on the inside or outside of the rectangular polar section vacuum chamber (1), the magnetization direction of the permanent magnet is perpendicular to the inside or outside of the rectangular polar section vacuum chamber (1) at different circumferential positions. The tangent of the outer surface corresponding to the circumferential position is inward or outward;

The rectangular planar coil (3) is placed vertically around the rectangular polar section vacuum chamber (1) and the standardized permanent magnet module (2) and is evenly distributed along the ring direction. For each rectangular planar coil, its corner is radius The same 90° arc structure.

Figure 2 and Figure 3 show the initial grid division of the standardized permanent magnet module (2) described in Figure 1, in which only the permanent magnet grid in the ring direction (0, π/6) is shown in the figure, where Figure 2 is the permanent magnet The three-dimensional view of the grid, Figure 3 is the top view of Figure 2. On the top and bottom of the vacuum chamber (1) with rectangular polar cross-section, the permanent magnets are divided into grids in the Cartesian coordinate system with the center of the device as the origin, and the corresponding sides of the length, width and height of the magnet block are parallel to the Cartesian coordinate system Corresponding to the X, Y, and Z coordinate axes; on the inside and outside of the vacuum chamber (1) with a rectangular polar section, the permanent magnets are meshed in the Cartesian coordinate system with the center of the device as the origin corresponding to the large column coordinate system, For the inner and outer magnets, first divide a layer of permanent magnet grids uniformly along the longitudinal (Z) and circumferential (Φ) directions at the position of the smallest radius in the radial direction (R) of the respective magnet division areas, and then use the corresponding first layer The permanent magnet grid is extended radially (R) from the starting point to the boundaries of the respective designated magnet design regions.

The specific arrangement scheme of the standardized permanent magnet module (2) is designed on the initial magnet grid shown in Fig. 2 and Fig. 3 according to the design method developed by the design strategy proposed in the published patent CN202011636945.4.

The rectangular polar section vacuum chamber (1) shown in Figure 1 can replace the rectangular polar section with regular shapes such as pentagons, hexagons, heptagons, and octagons according to design requirements, and the corresponding positions can also be arranged. The magnetization direction points to or away from the standardized permanent magnet module (2) of the vacuum chamber. The shape of the magnet block of the above-mentioned standardized permanent magnet module (2) can also be replaced by other regular shapes, including: parallelogram prism, triangular prism, trapezoidal prism and other shapes that can be obtained by splitting and combining regular cuboid shapes.

In addition, the simplified permanent magnet stellarator device shown in Figure 1 can increase the poloidal field coil system for plasma breakdown, heating and position control, as shown in Figure 4, the poloidal field coil system includes a central spiral Conduit (5) and field balance coil (6). The central solenoid (5) is arranged at the center of the device, and the balance field coil (6) is arranged at the periphery of the device, the number of which can be adjusted according to design requirements.

The parts not described in detail in the present invention belong to the well-known technology in the art.

Although the illustrative specific embodiments of the present invention have been described above, so that those skilled in the art can understand the present invention, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, As long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present invention are included in the protection list.

Claims (5)

1. A simplified permanent magnet stellarator device, including a rectangular poloidal section vacuum chamber (1) for containing plasma (4), a standardized permanent magnet module (2), and a rectangular planar coil (3), which Features: The vacuum chamber (1) with a rectangular polar cross section has a rectangular polar cross section, and is a circumferentially symmetrical structure as a whole, its inner and outer shapes are curved surfaces, and its top and bottom are flat; All magnet blocks in the standardized permanent magnet module (2) are cuboids with the same shape and size, and each magnet is uniformly magnetized along a direction perpendicular to its respective surface; The standardized permanent magnet module (2) is installed outside the vacuum chamber (1) with a rectangular polar cross section, there is no vacancy inside each row of magnets composed of magnet blocks, and the magnetization direction of all magnet blocks in the same row is the same; The magnetization direction of the standardized permanent magnet module (2) points to or departs from the vacuum chamber (1) with a rectangular polar cross section, wherein, at the top or bottom of the vacuum chamber (1) with a rectangular polar cross section, the magnetization direction of the permanent magnet is perpendicular to The top or bottom plane is upward or downward, and on the inside or outside of the rectangular polar section vacuum chamber (1), the magnetization direction of the permanent magnet is perpendicular to the inside or outside of the rectangular polar section vacuum chamber (1) at different circumferential positions. The tangent of the outer surface corresponding to the circumferential position is inward or outward; The rectangular planar coil (3) is placed vertically around the rectangular polar section vacuum chamber (1) and the standardized permanent magnet module (2); There is a certain radian at the corner of the rectangular planar coil (3). 2. A simplified permanent magnet stellarator device according to claim 1, characterized in that: the rectangular polar section vacuum chamber (1) replaces the rectangular polar section with a pentagon according to design requirements, six Polygonal, heptagonal, octagonal regular polygonal shapes, and the corresponding position also arranges the standardized permanent magnet module whose magnetization direction points to or deviates from the vacuum chamber. 3. A simplified permanent magnet stellarator device according to claim 1, characterized in that: the shape of the magnet block in the standardized permanent magnet module (2) can be replaced by other regular shapes, including: parallelogram prism , triangular prism, and trapezoidal prism, these shapes are obtained by splitting and combining regular cuboid shapes. 4. A simplified permanent magnet stellarator device according to claim 1, characterized in that: the magnet blocks in the standardized permanent magnet module (2) have the same residual magnetism, but the magnet blocks in different positions Choose different remanence strength according to design requirements. 5. a kind of simplified permanent magnet stellarator device according to claim 1, is characterized in that: The device also includes a poloidal field coil system, the poloidal field coil system includes a central solenoid (5) and a balance field coil (6); the central solenoid (5) is arranged in the center of the device; One or more balanced field coils (6) are arranged on the periphery of the device.

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