High-temperature superconducting magnet achieving uniform critical current density using dissimilar metal wire materials, and design parameter determination method thereof

Abstract

The present invention relates to a high-temperature superconducting magnet and, more specifically, to: a high-temperature superconducting magnet achieving uniform critical current density using dissimilar metal wire materials; and a design parameter determination method thereof. To this end, in a high-temperature superconducting (HTS) magnet (100) formed by stacking an HTS coil (50) having a tape-type HTS conductor wire material wound thereon, the HTS coil (50) comprises: a first metal wire material (110) wound on the HTS coil (50); and a second metal wire material (130) that is made of a different metal from the first metal wire material (110) and wound while at least partially overlapping the first metal wire material (110) in the longitudinal direction of the first metal wire material (110), thereby forming a composite winding portion (140). Accordingly, the HTS magnet achieving uniform critical current density using dissimilar metal wire materials is provided, wherein the uniformity of the critical current density increases on the longitudinal cross-section of the HTS magnet (100).

Description

High-temperature superconducting magnet realizing uniform critical current density with dissimilar metal wires and method for determining the same's design parameters

[0001] The present invention relates to a high-temperature superconducting magnet, and more specifically, to a high-temperature superconducting magnet that achieves a uniform critical current density using a dissimilar metal wire and a method for determining the design parameters thereof.

[0002] FIG. 1 is an example of a high-temperature superconducting magnet being used in a brain magnetic resonance imaging (MRI) device, FIG. 2 is a cross-sectional view of a high-temperature superconducting (HTS) magnet, and FIG. 3 is a cross-sectional photograph of a high-temperature superconducting magnet. As shown in FIG. 1 to FIG. 3, the coil for the high-temperature superconducting magnet is a tape-shaped wire and is made into an electromagnet by continuously winding it onto a bobbin.

[0003] Also, Fig. 4 is a conceptual diagram showing the direction of the current and magnetic field of a high-temperature superconducting wire, and Fig. 5 is a graph showing the relationship between the direction of the magnetic field of the high-temperature superconducting wire and the critical current. As shown in Figs. 4 and 5, when designing a high-temperature superconducting magnet, the operating current is designed to be lower than the critical current, which is the maximum current that the high-temperature superconducting wire can carry, and the critical current has the characteristic of being affected by both the strength and direction of the magnetic field applied to the high-temperature superconducting wire.

[0004] In particular, the critical current drops significantly as the magnetic field applied to the tape-type high-temperature superconducting wire approaches the vertical direction (based on the 0° direction arrow in Fig. 4), and increases as it approaches the horizontal direction (based on the 90° direction arrow in Fig. 4). For example, as shown in Fig. 5, it can be confirmed that the critical current drops significantly to 200A when the magnetic field is in the vertical direction (the 0° region of the X-axis).

[0005] Figure 6 is a graph schematically showing the results of a magnetic field simulation of a high-temperature superconducting magnet, and Figure 7 is a graph showing the distribution of the critical current margin of the high-temperature superconducting magnet according to the simulation results of Figure 6. Here, margin is defined as the ratio of operating current to critical current.

[0006] As shown in Figures 6 and 7, it can be seen that as one moves toward the edge (top / bottom) of the superconducting magnet, the strength of the magnetic field applied to the wire weakens, but the vertical magnetic field component increases, so the critical current at the edge is lower than at the center.

[0007] To address this, Multi-Width (MW) technology has conventionally been applied. MW technology is a design method in which wires with a larger cross-sectional area (higher critical current) are placed at the edges to solve the problem of having to lower the overall design current of a high-temperature superconducting magnet as the critical current at the edges decreases. Figure 8 is a graph showing the critical current margin distribution of a high-temperature superconducting magnet when Multi-Width (MW) high-temperature superconducting wires are wound. As shown in Figure 8, conventionally, coils wound by grouping wires of different Multi-Width (MW1, MW2, MW3) were arranged. In other words, because the operating current had to be increased to generate a strong magnetic field, the critical current, which is the maximum current that can flow through the magnet, had to be increased.

[0008] However, multi-width (MW) technology as shown in Fig. 8 had the disadvantage that the size of the magnet (height, outer diameter) had to be increased to increase the uniformity of the magnetic field in the central space. In addition, strong metal had to be co-winded to relieve mechanical stress, and in situations where the current changes rapidly, such as in a quench situation, a screening current equal to the critical current was generated in the coil, and the high screening current induced a strong force and caused damage to the magnet.

[0009] FIG. 9a shows the design shape of a high-temperature superconducting magnet with only multi-width applied, and FIG. 9b is a graph showing the critical current margin distribution of the high-temperature superconducting magnet shown in FIG. 9a. As can be seen from FIG. 9a and FIG. 9b, the high-temperature superconducting magnet had to be larger to improve magnetic field uniformity, which causes additional problems such as increased cooling load and increased mechanical stress due to increased superconducting wire cost and weight.

[0010] Furthermore, there is a fundamental problem in solenoid-type magnets where it is difficult to avoid a reduction in the critical current of superconducting wires, which are significantly affected by the angle of the magnetic field. Since regions with high critical current magnitudes induce large currents in fault situations, regions where the critical current is unnecessarily high must be eliminated.

[0011] Prior art literature

[0012] Patent documents

[0013] (Patent Document 1) 1. Patent Publication No. 10-2022-0059886 (Superconducting wire and method for manufacturing the same),

[0014] (Patent Document 2) 2. Patent Registration No. 10-1158747 (Method for forming a ceramic wire, system for forming a ceramic wire, and superconducting wire using the same),

[0015] (Patent Document 3) 3. Patent Registration No. 10-1256561 (Superconductor coil and method of manufacturing the same).

[0016] Accordingly, the present invention has been devised to solve the above-mentioned problems, and the objective of the present invention is to provide a high-temperature superconducting magnet that achieves a uniform critical current density using a heterogeneous metal wire, which improves the uniformity of the critical current density of each coil by appropriately arranging a composite winding (co-winding) of heterogeneous materials, and a method for determining the design parameters thereof.

[0017] However, the technical problems to be solved by the present invention are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0018] Furthermore, the present invention aims to provide a high-temperature superconducting magnet that achieves a uniform critical current density using the heterogeneous metal wire of the present invention, and a method for determining the design parameters thereof.

[0019] [National R&D projects that supported this invention]

[0020] [Project ID] 1711191384

[0021] [Assignment No.] 2022M3I9A1072464

[0022] [Ministry Name] Ministry of Science and ICT

[0023] [Name of Project Management (Specialized) Agency] National Research Foundation of Korea

[0024] [Research Project Name] Development of High-Temperature Superconducting Magnet Technology

[0025] [Research Project Title] Core Device of Ultra-High Magnetic Field Highly Uniform Solenoid-Type High-Temperature Superconducting Magnet

[0026] Alcohol development

[0027] [Name of Project Performing Organization] Korea Basic Science Institute

[0028] [Research Period] 2024.01.01 ~ 2024.12.31

[0029] To achieve the above technical objective, a high temperature superconducting magnet (100) is provided in which a high temperature superconducting coil (50) wound with a tape-shaped high temperature superconducting (HTS) wire is stacked, wherein the high temperature superconducting coil (50) comprises: a first metal wire (110) wound on the high temperature superconducting coil (50); and a second metal wire (130) made of a different metal from the first metal wire (110) and formed a composite winding portion (140) by being wound overlapping the first metal wire (110) at least a portion of which is wound along the longitudinal direction of the first metal wire (110). The high temperature superconducting magnet is characterized by having a higher uniformity of critical current density on the cross-sectional surface of the high temperature superconducting magnet (100).

[0030] In addition, the first metal wire (110) is copper, and the second metal wire (130) is steel, preferably stainless steel.

[0031] In addition, the ratio of the winding radius of the first metal wire (110) to the winding radius of the composite winding section (140) is 1:9 to 4:6.

[0032] Additionally, each of the stacked high-temperature superconducting coils (50) may have a ratio of radii that differs along the axial direction.

[0033] Additionally, the stacked high-temperature superconducting coil (50) includes at least a bottom coil (150) at the bottom and a top coil (160) at the top, and the width (W) of the wire can be increased from the bottom coil (150) in the direction of the top coil (160).

[0034] In addition, the width (W) of the wire increases stepwise from 4 mm to 15 mm in the direction from the bottom coil (150) to the top coil (160).

[0035] In addition, the inner diameter of the high-temperature superconducting coil (50) is in the range of 70 to 100 mm, and the outer diameter is in the range of 180 to 250 mm.

[0036] In addition, the composite winding section (140) forms the outer diameter of the high-temperature superconducting coil (50).

[0037] The objective of the present invention as described above is, in another category, a method for determining design parameters of a high-temperature superconducting magnet as described above, comprising the steps of: receiving an initial solution set of design parameters including the number of coils, operating current, size, multi-width ratio, and the ratio of a first metal wire (110) and a second metal wire (130) of the high-temperature superconducting magnet (S100) in a computer (S100); simulating at least one of the magnetic field strength, magnetic field uniformity, critical current, and wire length of the high-temperature superconducting magnet (100) in a simulation program based on the initial solution set (S120); determining the suitability of the solution set based on the simulation results in a simulation program (S140); determining whether the change in suitability of the solution set is within an allowable range at a predetermined number of non-updating intervals or more (S160); and determining the solution set as the final solution set if, as a result of the determination, the change is within an allowable range at a number of non-updating intervals or more (S180). This can also be achieved by a method for determining design parameters of a high-temperature superconducting magnet that implements a uniform critical current density using a heterogeneous metal wire, characterized by including a step (S170) of generating a new solution set by applying a genetic algorithm to the solution set, except for the determination step (S180), and then returning to the simulation step (S120).

[0038] Additionally, the genetic algorithm performs at least one of the operations of modifying the parameters of the solution set, replacing them with different parameters, or selecting them as different parameters.

[0039] According to one embodiment of the present invention, by appropriately arranging a composite winding (co-winding) of heterogeneous materials, the magnetic field in a region where the angle of the magnetic field deviates from horizontal can be aligned horizontally, thereby minimizing the reduction in critical current occurring at the upper part of a multi-width (MW) coil. This means that a higher operating current can be flowed.

[0040] Furthermore, according to the present invention, miniaturization of a high-temperature superconducting magnet can be achieved by improving the uniformity of the central magnetic field using critical current density control. This results in reduced manufacturing costs and space savings.

[0041] In addition, by increasing the critical current in the region where the critical current decreases significantly, the amount of shielding current generated during a fault can be reduced due to margin equalization.

[0042] In addition, according to the present invention, the amount of wire consumed can be reduced by changing the direction of the magnetic field inside the winding to a favorable direction by adjusting the thickness of the wire or composite winding in a specific section to be thinner or thicker during the design.

[0043] However, the effects obtainable from the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below.

[0044] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0045] FIG. 1 is an example of a high-temperature superconducting magnet being used in a brain magnetic resonance imaging (MRI) device.

[0046] Figure 2 is a cross-sectional view of a high-temperature superconducting magnet,

[0047] Figure 3 is a cross-sectional photograph of a high-temperature superconducting magnet,

[0048] FIG. 4 is a conceptual diagram showing the direction of the current and magnetic field of a high-temperature superconducting wire,

[0049] Figure 5 is a graph showing the relationship between the magnetic field direction and the critical current of a high-temperature superconducting wire,

[0050] Figure 6 is a graph schematically showing the results of a magnetic field simulation of a high-temperature superconducting magnet,

[0051] Figure 7 is a graph showing the critical current margin distribution of a high-temperature superconducting magnet according to the simulation results of Figure 6,

[0052] FIG. 8 is a graph showing the critical current margin distribution of a high-temperature superconducting magnet when a multi-width high-temperature superconducting wire is wound.

[0053] FIG. 9a shows the design shape of a high-temperature superconducting magnet with only multi-width applied,

[0054] FIG. 9b is a graph showing the critical current margin distribution of the high-temperature superconducting magnet illustrated in FIG. 9a,

[0055] FIG. 10 is a schematic perspective view of a winding device for winding a coil for a high-temperature superconducting magnet according to the present invention.

[0056] FIG. 11a is a cross-sectional view of a high-temperature superconducting magnet that achieves a uniform critical current density using a heterogeneous metal wire according to an embodiment of the present invention.

[0057] FIG. 11b is a graph showing the critical current margin distribution of a high-temperature superconducting magnet according to FIG. 11a,

[0058] FIG. 12 is a flowchart schematically illustrating a method for determining design parameters of a high-temperature superconducting magnet according to the present invention.

[0059] Below, with reference to the attached drawings, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. However, since the description of the present invention is merely an example for structural or functional explanation, the scope of the present invention should not be interpreted as being limited by the embodiments described in the text. That is, since the embodiments are subject to various modifications and may take various forms, the scope of the present invention should be understood to include equivalents capable of realizing the technical concept. Furthermore, the objectives or effects presented in the present invention do not imply that a specific embodiment must include all of them or only such effects; therefore, the scope of the present invention should not be understood as being limited by them.

[0060] The meaning of the terms described in this invention should be understood as follows.

[0061] Terms such as "first" and "second" are intended to distinguish one component from another, and the scope of rights shall not be limited by these terms. For example, the first component may be named the second component, and similarly, the second component may be named the first component. When a component is referred to as being "connected" to another component, it should be understood that it may be directly connected to that other component, or that there may be other components in between. Conversely, when a component is referred to as being "directly connected" to another component, it should be understood that there are no other components in between. Meanwhile, other expressions describing the relationship between components, such as "between" and "exactly between," or "adjacent to" and "directly adjacent to," shall be interpreted in the same manner.

[0062] A singular expression should be understood to include a plural expression unless the context clearly indicates otherwise, and terms such as "include" or "have" are intended to specify the existence of the set-up features, numbers, steps, actions, components, parts, or combinations thereof, and should be understood not to preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0063] Unless otherwise defined, all terms used herein have the same meaning as generally understood by those skilled in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having meanings consistent with the context of the relevant technology and should not be interpreted as having an ideal or overly formal meaning unless explicitly defined in this invention.

[0064] Composition of the embodiment

[0065] Hereinafter, the configuration of a preferred embodiment will be described in detail with reference to the attached drawings. FIG. 10 is a schematic perspective view of a winding device for winding a coil for a high-temperature superconducting magnet according to the present invention. As shown in FIG. 10, a winding shaft (20) and a winding table (40) rotate at a constant speed. A bobbin (30) is fitted onto the winding shaft (20). A first metal wire (110) of a certain length is wound onto the bobbin (30), and then the first metal wire (110) and the second metal wire (130) overlap to form a co-winding. As the first metal wire (110) and the second metal wire (130) are co-winded, they form the outer diameter of a coil (50) and have a predetermined width (W). The bobbin (30) and the pancake coil (50) produced in this way form an electromagnet.

[0066] FIG. 11a is a cross-sectional view of a high-temperature superconducting magnet that achieves a uniform critical current density using a heterogeneous metal wire according to an embodiment of the present invention. As shown in FIG. 11a, the high-temperature superconducting magnet (100) is formed by stacking high-temperature superconducting coils (50), which are wound with tape-shaped high-temperature superconducting (HTS) wires, in the Z-axis direction.

[0067] The second metal wire (130) is first wound onto a high-temperature superconducting coil (50) to form an inner diameter and is made of copper.

[0068] The second metal wire (130) is made of a different metal from the first metal wire (110), and at least a portion of it is wound overlapping the first metal wire (110) along the length direction of the first metal wire (110) to form a composite winding portion (140). The second metal wire (130) can be a metal material with a strength greater than copper (e.g., steel, stainless steel).

[0069] In the cross-section of the high-temperature superconducting magnet (100) shown in FIG. 11a, the ratio of the winding radius (cross-sectional length) of the first metal wire (110) to the winding radius (cross-sectional length) of the composite winding part (140) is 1:9 to 4:6. If the winding radius of the first metal wire (110) is less than 1, the magnetic field formation becomes too weak, and if it exceeds 4, the magnetic field may become uneven.

[0070] Additionally, as shown in FIG. 11, the ratio of the radii of each high-temperature superconducting coil (50) stacked in the Z-axis direction may differ along the axial direction. That is, in the lower region, the ratio of the winding radius of the first metal wire (110) to the winding radius of the composite winding section (140) may be 3:7, in the middle region it may be 4:6, and in the upper region it may be 2:8.

[0071] Additionally, the stacked high-temperature superconducting coil (50) includes a plurality of high-temperature superconducting coils (50) between the bottom coil (150) and the top coil (160), and is configured so that the width (W) of the wire increases from the bottom coil (150) toward the top coil (160). This increase in width can be configured to increase linearly or stepwise. In this embodiment, the width (W) of the wire increases stepwise from 4 mm toward the top coil (160) from the bottom coil (150) toward 15 mm. That is, five high-temperature superconducting coils (50) having the width (W1) of the bottom coil (150) are stacked, five high-temperature superconducting coils (50) having a larger width are stacked on top of them, and finally, two high-temperature superconducting coils (50) having the width (Wn) of the top coil (160) are stacked.

[0072] The inner diameter of such high-temperature superconducting coil (50) is in the range of 70 to 100 mm, and the outer diameter is in the range of 180 to 250 mm. Optionally, the inner and outer diameters may be changed according to capacity or design specifications.

[0073] Figure 11b is a graph showing the critical current margin distribution of a high-temperature superconducting magnet according to Figure 11a. Here, margin is defined as the ratio of operating current to critical current. As shown in Figure 11b, it can be seen that the region where the critical current is uniform (red) has been significantly expanded compared to Figures 7, 8, and 9b.

[0074] Operation of the example

[0075] Hereinafter, the operation of a preferred embodiment will be described in detail with reference to the attached drawings. FIG. 12 is a flowchart schematically illustrating a method for determining design parameters of a high-temperature superconducting magnet according to the present invention.

[0076] First, an initial solution set of design parameters including the number of coils, operating current, size, multi-width ratio of the high-temperature superconducting magnet, and the ratio of the first metal wire (110) to the second metal wire (130) is generated and input into a computer (S100). Data such as the material, length, width, and thickness of the first and second metal wires (110, 130) may also be input.

[0077] Next, the simulation program simulates at least one of the magnetic field strength, magnetic field uniformity, critical current, and wire length of the high-temperature superconducting magnet (100) based on the initial solution set (S120). A commercially available simulation program was used.

[0078] Next, the simulation program determines the suitability of the solution set based on the simulation results (S140). The suitability is determined as the magnetic field strength is closer to the allowable range of a predetermined design value. Additionally, the uniformity of the magnetic field is also determined as suitable as it is closer to a predetermined allowable value. The critical current is determined as suitable as it is greater than the operating current. The wire length is determined as suitable as it is shorter.

[0079] Next, it is determined whether the change in fitness of the solution set is within an allowable range at a predetermined number of non-updating numbers or more (S160).

[0080] If, as a result of the judgment, the change is within the allowable range for more than the number of non-updating cycles, the solution set is determined as the final solution set (S180). That is, if there is almost no change in fitness while reaching a predetermined number of non-updating cycles (e.g., 100 cycles), the current best fit solution can be determined as the final solution set.

[0081] If, as a result of the judgment, the number of non-updating parameters is less than a predetermined number or the change in fitness of the solution set exceeds an allowable range, it is considered that the parameters have not yet been optimized, so the simulation program applies a genetic algorithm to the solution set to generate a new solution set, and then returns to the simulation step (S120) (S170). At this time, the genetic algorithm performs at least one of the operations of modifying the parameters of the solution set, replacing them with different parameters, or selecting them as different parameters.

[0082] For example, an increase in the length of the second metal wire (130) means an increase in the radial cross-sectional length of the composite winding section (140) (i.e., an increase in the inner diameter of the composite winding section (140)). This is because the outer diameter of the composite winding section (140) is geometrically limited.

[0083] The length increase or decrease of the second metal wire (130) is sequentially applied to each coil (50) in the Z-axis direction from the lower coil (150), and the length increase or decrease may also be random.

[0084] [Table 1] is a comparison table of optimal designs comparing conventional technology and the present invention.

[0085] MW PPM 자기장 @Ic 권선방법 권선 보아 최대 Hoop 응력 Maximum Hoop Stress @ IC Winding Length (T= 4mm) 종래기술 5MW <300 >23.53T Co-winding(135+50) 78mm 192 Mpa 266 MPa 61.92 Km 실시예 Nl(85)+CW(30) 282 MPa 390 MPa 36.64 Km

[0086] As can be seen from [Table 1], it can be confirmed that the amount of wire used in the superconducting magnet of the present invention has been significantly reduced from 61.92 km to 36.64 km.

[0087] As described above, the detailed description of the preferred embodiments of the present invention disclosed is provided to enable those skilled in the art to implement and practice the present invention. Although the present invention has been described with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the scope of the invention. For example, those skilled in the art may utilize each configuration described in the embodiments described above in combination with one another. Accordingly, the present invention is not intended to be limited to the embodiments shown herein, but to be given the broadest scope consistent with the principles and novel features disclosed herein.

[0088] The present invention may be embodied in other specific forms without departing from the spirit and essential features of the invention. Accordingly, the above detailed description should not be interpreted restrictively in all respects but should be considered exemplary. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention. The invention is not intended to be limited to the embodiments shown herein, but to be given the broadest possible scope consistent with the principles and novel features disclosed herein. Furthermore, embodiments may be constructed by combining claims that are not explicitly related in the claims, or by including them as new claims through amendments made after filing.

[0089] Explanation of the symbols

[0090] 20 : Winding axis,

[0091] 30 : Bobbin,

[0092] 40 : Winding table,

[0093] 50 : High-temperature superconducting coil,

[0094] 100 : High-temperature superconducting magnet,

[0095] 110 : 1st metal wire,

[0096] 130 : 2nd metal wire,

[0097] 140 : Composite winding section,

[0098] 150 : Bottom coil,

[0099] 160 : Top coil,

[0100] W, W1, W2,...., Wn-1, Wn : Width of the wire.

Claims

1. A high temperature superconducting magnet (100) formed by stacking high temperature superconducting coils (50) wound with tape-shaped high temperature superconducting (HTS) wires, The above high-temperature superconducting coil (50) is, A first metal wire (110) wound on the above high-temperature superconducting coil (50); and A high-temperature superconducting magnet that achieves a uniform critical current density using a heterogeneous metal wire, characterized by having a second metal wire (130) made of a different metal from the first metal wire (110) and formed by winding at least a portion of the second metal wire (130) along the longitudinal direction of the first metal wire (110) in overlap with the first metal wire (110) to form a composite winding portion (140).

2. In Paragraph 1, A high-temperature superconducting magnet that achieves a uniform critical current density using heterogeneous metal wires, characterized in that the first metal wire (110) is copper and the second metal wire (130) is steel.

3. In Paragraph 2, A high-temperature superconducting magnet that achieves a uniform critical current density using a dissimilar metal wire, characterized in that the above-mentioned steel is stainless steel.

4. In Paragraph 1, A high-temperature superconducting magnet that achieves a uniform critical current density using heterogeneous metal wires, characterized in that the ratio of the winding radius of the first metal wire (110) to the winding radius of the composite winding section (140) is 1:9 to 4:

6.

5. In Paragraph 4, A high-temperature superconducting magnet that achieves a uniform critical current density using heterogeneous metal wires, characterized in that each of the stacked high-temperature superconducting coils (50) has a ratio of radii that differs along the axial direction.

6. In Paragraph 1, The stacked high-temperature superconducting coil (50) is, It includes at least a bottom coil (150) at the lowest end and a top coil (160) at the highest end, A high-temperature superconducting magnet that achieves a uniform critical current density using a heterogeneous metal wire, characterized in that the width (W) of the wire increases from the lower coil (150) in the direction of the upper coil (160).

7. In Paragraph 6, A high-temperature superconducting magnet that achieves a uniform critical current density using a heterogeneous metal wire, characterized in that the width (W) of the wire increases stepwise from 4 mm to 15 mm in the direction from the lower coil (150) to the upper coil (160).

8. In Paragraph 1, A high-temperature superconducting magnet that achieves a uniform critical current density using a heterogeneous metal wire, characterized in that the inner diameter of the high-temperature superconducting coil (50) is in the range of 70 to 100 mm and the outer diameter is in the range of 180 to 250 mm.

9. In Paragraph 1, A high-temperature superconducting magnet that achieves a uniform critical current density using a heterogeneous metal wire, characterized in that the above composite winding section (140) forms the outer diameter of the above high-temperature superconducting coil (50).

10. A method for determining design parameters of a high-temperature superconducting magnet according to any one of claims 1 to 9, A step (S100) in which the computer receives an initial solution set of design parameters including the number of coils, operating current, size, multi-width ratio, and the ratio of the first metal wire (110) and the second metal wire (130) of the high-temperature superconducting magnet; Step (S120) in which a simulation program simulates at least one of the magnetic field strength, magnetic field uniformity, critical current, and wire length of a high-temperature superconducting magnet (100) based on the above initial solution set; A step (S140) in which the simulation program determines the goodness of fit of the solution set based on the simulation results; A step (S160) of determining whether the change in fitness of the solution set is within an allowable range at a predetermined number of non-updating numbers or more; A step (S180) of determining the solution set as the final solution set if, based on the above judgment result, the change is within the allowable range at or above the above non-updating number; A method for determining design parameters of a high-temperature superconducting magnet that achieves a uniform critical current density using a heterogeneous metal wire, characterized by including: a step (S170) of generating a new solution set by applying a genetic algorithm to the solution set, except for the above determination step (S180), and then returning to the above simulation step (S120).

11. In Paragraph 10, A method for determining design parameters of a high-temperature superconducting magnet, characterized in that the above genetic algorithm performs at least one of the operations of modifying the parameters of the solution set, replacing them with other parameters, or selecting them with other parameters.

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