Methods for reinforcing, quench protection, and stabilizing large all-metal superconducting magnets

Abstract

A technique for enabling structural reinforcement and thermal stabilization of conductor windings in a superconducting coil configuration is disclosed, as well as a superconducting coil manufactured by said technique. The superconducting coil generally includes a coil winding of a superconducting material defining a conductive channel having an inlet and an outlet, wherein the coil winding is (i) wound helically around a curved surface about a central axis, or (b) wound as a helical layer about a curved surface about a central axis. One or more coil windings are operably bonded to at least one co-wound reinforcement layer, which is located between at least two adjacent superconducting coil windings or between layers of superconducting coil windings. This method can significantly improve the space factor in the coil winding while simplifying quench protection, enabling the construction of all-metal high-field magnets with large bores and high magnetic fields.

Description

Technical Field

[0001] Cross-Reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 53,785, filed on August 15, 2023, the entire contents of which are incorporated herein by reference.

[0002] Statement on Federally Sponsored Research or Development This invention was made with government support from the United States Government under Contract No. DE-AC02-09-CH 11466 awarded by the United States Department of Energy. The United States Government has certain rights in the invention.

[0003] Technical Field The present disclosure relates to a technology for improving large superconducting magnets to address one of the most difficult challenges regarding quench protection of large all-metal non-insulated superconducting magnets, specifically to a manufacturing technology for superconducting magnets that reduces manufacturing costs, improves the radiation resistance of coils, and enhances the structural integrity of coils. Background Art

[0004] Superconducting coils have numerous applications, including use in fusion reactors, commercial nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) applications, high-field accelerators for high-energy physics applications, and magnets for specific scientific discoveries (e.g., magnets for dark matter detectors at the space frontier).

[0005] Improvements to superconducting coils, particularly high-temperature superconducting (HTS) magnets, often appear promising in small-scale experiments, but when scaled up to the relatively high magnetic field and / or large bore required for practical real-world applications, they often fail to operate reliably and / or reproducibly, and / or become too expensive to be affordable. Summary of Invention

[0006] Superconducting coils can be provided in various forms. A superconducting coil generally includes multiple coil windings containing one or more superconducting materials (which may take the form of, for example, wires, tapes, or cables) that define conductive channels having inlet and outlet ports. One or more (preferably all) of the multiple coil windings may be operably coupled to at least one co-wound reinforcing layer. Typically, there are two variations of this configuration. In the first variation, the multiple coil windings may be wound helically around a curved surface about a central axis, and at least one co-wound reinforcing layer may be located between at least two adjacent superconducting coil windings. In the second variation, the multiple coil windings may be wound as helical layers around a curved surface about a central axis, and at least one co-wound reinforcing layer may be located between at least two adjacent superconducting coil windings, or between multiple layers of superconducting coil windings.

[0007] At least one reinforcing layer can be joined to at least two adjacent superconducting windings by friction, winding tension, and clamping force. Depending on the superconductor used, at least one reinforcing layer can be joined to at least two superconducting windings by soldering, brazing, diffusion bonding, welding, and conductive adhesive. At least one reinforcing layer can be joined to at least two adjacent windings after the superconducting coil has been wound by soldering, brazing, diffusion bonding, or adhesive bonding the reinforcing layer to the superconducting material and the rest of the coil pack.

[0008] At least one co-wound reinforcing layer may consist of a single layer. At least one co-wound reinforcing layer may consist of multiple layers. In some embodiments, multiple layers of different thicknesses (e.g., layer 1 being thicker than layer 2) may be used to improve performance integration or integrated coil performance during operation.

[0009] The thickness of at least one reinforcing layer may be constant. The thickness of at least one reinforcing layer at a first position may differ from the thickness of at least one reinforcing layer at a second position. In certain embodiments, the thickness of at least one reinforcing layer can be continuously varied, for example, by uniform or variable tapering of at least one reinforcing layer. In certain embodiments, the thickness of the reinforcing layer may vary between a set of separate thicknesses, with relatively short inclined sections between separate levels, for example, when the inclined section has a length of less than one turn of the coil.

[0010] The reinforcing layer may include a tightly bonded layer of copper, silicon, germanium, or silicon carbide, or a resistant or conductive coating such as boronation or carbide surface treatment. The location of the resistant or conductive coating for deployment within the coil winding pack can be determined by the coil design based on its integrated performance during operation.

[0011] At least one reinforcing layer may include a variety of materials such as carbon, silicon, germanium, silicon carbide, aluminum, copper, and / or silver. At least one reinforcing layer may include high-strength steel, superalloys (e.g., Hastelloy® superalloys, Inconel® superalloys, etc.), maraging alloys, or high-strength refractory alloys (e.g., those containing tantalum and / or tungsten). The specific material choice may depend on the application.

[0012] In various embodiments, methods for constructing superconducting electromagnets for structural reinforcement and quench protection can be provided. These methods may include coupling at least one reinforcing layer to a superconducting coil. Alternatively, they may include embedding at least one reinforcing layer between at least two windings of a superconducting coil.

[0013] At least one reinforcing layer can be joined to at least two adjacent superconducting windings by friction, winding tension, and clamping force. At least one reinforcing layer can be joined to at least two superconducting windings by soldering, brazing, diffusion bonding, welding, and conductive adhesive. After winding the superconducting coil, at least one reinforcing layer can be joined to at least two adjacent windings by soldering, brazing, diffusion bonding, or adhesive bonding to the superconducting material and the rest of the coil pack.

[0014] Depending on its application, this method may include adjusting at least one co-wound reinforcing layer to provide a desired turn-to-turn electrical contact resistance in an all-metal coil.

[0015] This method may include selecting at least one co-wound reinforcement layer to optimize one or more variables, such as strength, specific heat, electrical conductivity, thermal conductivity, and / or cost.

[0016] If at least one co-wound reinforcement layer is formed of multiple layers, the method may include selecting at least one of the multiple layers to optimize strength, specific heat, electrical conductivity, thermal conductivity and / or cost.

[0017] This method may include determining one or more thicknesses of at least one co-wound reinforcement layer to match a desired distribution of strength, heat capacity, electrical conductivity, and thermal conductivity.

[0018] This method may involve configuring the material or structure of at least one co-wound reinforcing layer to achieve a desired electrical or thermal resistance between turns of a superconducting coil. For example, the electrical or thermal resistance between turns can be adjusted by applying a resistant or conductive coating (e.g., boronization surface treatment) to at least one co-wound reinforcing layer.

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the foregoing summary of the invention and the following detailed description of embodiments, serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] [Figure 1] Figure 1 is a diagram of a magnet assembly. [Figure 2] Figure 2 is a side view of a coil section. [Figure 3] Figure 3 is a side cross-sectional view of an embodiment of a coil section showing a portion of an axial layer as shown in Figure 2. [Figure 4] Figure 4 is a side cross-sectional view of another embodiment of the coil section shown in Figure 3. [Figure 5] Figure 5 is a diagram of a co-wound reinforcement layer having a thickness gradient. [Figure 6A-6B] Figures 6A to 6B are side cross-sectional views of other embodiments of a coil section. [Figure 7] Figure 7 is a diagram of a solenoid and magnetic lines of force. [Figure 8] Figure 8 is a plot showing the stress distribution in a cross-section of an embodiment of a winding pack having co-wound structural reinforcement. [Figure 9] Figure 9 is an image of a 3D model of a magnet assembly. [Figure 10] Figure 10 is an image of a prototype magnet assembly. [Figure 11] Figure 11 is a side view of a non-circular shaped toroidal magnetic field coil, and a cross-sectional view of a coil section having reinforcement of two different thicknesses. [Figure 12] Figure 12 is a top view of a toroidal magnetic field array combined with a central solenoid and poloidal magnetic field coils. [Figure 13] Figure 13 is a flowchart of the present method. MODES FOR CARRYING OUT THE INVENTION

[0021] It should be understood that the attached drawings are not necessarily to actual size and illustrate various features in a somewhat simplified manner to illustrate the basic principles of the present invention. For example, the specific design features of the series of operations disclosed herein, such as the specific dimensions, orientation, position, and shape of the various components shown, will be determined in part by the specific intended use and operating environment. Some features of the illustrated embodiments are enlarged or modified compared to other parts to facilitate visualization and clear understanding. In particular, thin features may be depicted thicker, for example, for clarity and explanation.

[0022] Detailed explanation Methods for reinforcing, quench-protecting, and stabilizing large, all-metal, high-field superconducting magnets are disclosed. More specifically, methods for constructing superconducting electromagnetic coils of any size and field strength without the use of conventional electrical insulators, which provide intrinsic superconductor quench protection, are disclosed. This makes it possible to scale up the advantages of all-metal, non-insulated superconducting coil technology (see, for example, U.S. Patent No. 4,760,365 and U.S. Patent No. 9,117,578) to the large coils required for nuclear fusion, MRI, and other applications.

[0023] The approach of this disclosure is a method and process that enables simultaneous structural reinforcement, thermal stabilization, and electrical stabilization of conductor windings in a superconducting coil configuration. The approach of this disclosure uses a co-wound, high-strength reinforcing layer that supports the Lorentz force when a voltage is applied to a high magnetic field and / or large-diameter superconducting electromagnet, without requiring other expensive and specialized structures to form the coil winding. This co-wound reinforcing layer is also designed to provide sufficient cryogenic heat capacity, thermal conductivity, and electrical conductivity necessary for quench protection of the superconducting coil.

[0024] The approach of this disclosure improves the coil's packing factor by optimizing the co-winding reinforcement for the coil's structural integrity and thermal stability. It also ensures coil protection during quenching, where the co-winding structural reinforcement acts as a cold mass for thermal protection of the coil winding pack. This is particularly beneficial in expanding the applicability of all-metal coil designs by eliminating the need for costly quench protection systems that require complex and error-prone vacuum immersion (VPI) with epoxy resins or other insulators, or quench heaters in winding packs typically used for invasive and fragile optical fiber or acoustic quench sensors, or large superconducting coils in fusion, MRI, and other applications. Since it is extremely difficult to house these optical fiber sensors and quench heaters in tightly wound coil winding packs, the method of this disclosure significantly simplifies the coil structure and improves the reliability of the coil system. This method mitigates risks associated with high-field operation, such as structural failure due to localized stress exceeding the stress limit of the coil winding support structure (e.g., high localized stress induced by shielding current), or peak temperature exceeding the limit during quenching in the winding pack.

[0025] The all-metal construction of high-field, large-diameter coils eliminates internal insulation, enabling efficient cooling of the winding pack and allowing for conductive cooling, thus eliminating the need for large amounts of helium or other cryogenic fluids or gases. This also simplifies the coil structure and reduces costs.

[0026] Therefore, the method disclosed herein enables efficient stress and thermal management of coil winding packs of all-metal high-temperature superconducting (HTS) magnets capable of stable operation at high magnetic fields, while also reducing the consumption of cryogenic fluids and cooling costs.

[0027] One key feature of the method disclosed herein is its ability to integrate coil stress and thermal protection / cooling management for high-field magnet windings by optimizing co-winding structural reinforcement and establishing control of cold mass added when engineering inter-turn contact resistance heating for quench protection. This allows for more uniform distribution of thermal energy during quenching and reduces the risk of slow cryogenic cooling response (against rapid localized heating). Conventional structural reinforcement methods and conventional methods for coil quench protection have been separate and unintegrated, complicating the design of winding packs.

[0028] The approach described herein simplifies coil design and performance by integrating and optimizing the coil winding pack structure support (stress management) and the coil quench protection system (thermal management and power dissipation) together. In large, high-field magnets such as those used in nuclear fusion and MRI, it is crucial to optimize the coil support structure for a desirable winding pack stress distribution while ensuring sufficient cold mass (non-superconducting portion) for quench protection to minimize cryogenic cooling requirements.

[0029] The method disclosed herein enables stress optimization and thermal management of the coil winding pack in a high-field all-metal superconducting coil, thereby reducing cooling requirements and enabling the manufacture of low-cost, high-field magnets with flexible sizing and reliable operation compared to equivalent superconducting magnets constructed by other methods in which stress management and coil quench protection of the coil winding pack are completely separated.

[0030] Furthermore, the method disclosed herein is readily extendable to different magnet sizes and shapes (related to fusion magnets) and provides a design for co-wound reinforcement coils suitable for automation.

[0031] More specifically, a coil winding method using co-wound structural reinforcement is disclosed, and a process for integrating structural reinforcement into coil windings is disclosed, in which the reinforcement is used as cold mass for coil quench protection by carefully designing and selecting the reinforcement to balance stress management and thermal management, while varying the thickness to optimize the winding pack stress distribution in high-field superconducting magnets. Furthermore, the co-wound reinforcement layer can also be designed to control thermal conduction along and across the superconducting winding, dispersing heat dissipation, reducing temperature rise, and protecting against quench damage.

[0032] A superconducting coil can be provided in various forms. Referring to Figure 1, the magnet assembly (100) may include various sections that can be formed around a central axis (101). These sections may include a coil section (110) containing a superconducting coil as disclosed herein. These sections may also include a terminal ring (120), which may be made of a thermally conductive material such as copper, or a structural material such as stainless steel or INCONEL® superalloy. These sections may also include one or more preload rings (130), which may also be made of metal. These sections may also include a central mandrel (140), which may have a portion (141) extending axially from the magnet assembly (e.g., the terminal ring, coil section, and preload section), such as a hollow cylindrical portion.

[0033] Referring to Figure 2, the coil section (110) can include n axial layers (200(1), 200(2), ..., (200(n)), where n is, for example, at least 1, at least 2, at least 3, at least 5, at least 10, at least 20, or at least 50, and is not less than or equal to 1000, not less than or equal to 500, not less than or equal to 250, or not less than or equal to 100, and includes all of these ranges and sub-ranges thereof.

[0034] Two variations will be described. Generally, the coil may be wound as a series of pancake-type or double-pancake-type subcoils in which windings (typically composed of superconducting wires, tapes, or cables, which may include embedded wires and / or tapes) and co-wound reinforcing materials are stacked radially, or as a layer-wound coil in which the reinforcing materials may or may not span one or more windings within a layer and be aligned with the superconductor. These terms will be familiar to those skilled in the art.

[0035] Referring to Figure 2, in the first modified example, within each axial layer, superconducting material and co-winding material may be alternately arranged radially outward from the central axis (101). Referring to Figure 3, the inner surface (305) of each layer is at a distance d1 (330) from the central axis (101) (d1>0). The superconducting coil includes a plurality of coil windings (310(1), 310(2), ...), each of which may be composed of one or more superconducting materials that define a conductive channel having an inlet and an outlet (e.g., the starting end of the inner winding (301) and the ending end of the outer winding (302)).

[0036] All-metal superconducting coils can be constructed from any suitable material, including low-temperature superconductors such as niobium-titanium (NbTi) and niobium-tin (Nb3n), high-temperature superconductors such as ReBCO, YBCO, and BSCCO, and medium-temperature superconductors such as magnesium diboride (MgB2). The superconductor winding can take the form of wire, tape, or a cable consisting of wire and tape.

[0037] Multiple coil windings may be operably joined to at least one co-winding reinforcement layer (320). Multiple coil windings can be wound helically around a curved surface around a central axis (101). Although a cylindrical arrangement is illustrated, it will be understood that the shape of the windings can be changed as needed to generate the desired magnetic field. For example, the cross-sectional area can be a rectangle with rounded corners, a "D" shape (see Figure 11), or any other arbitrary two-dimensional shape.

[0038] At least one co-wound reinforcing layer (320) can be placed between at least two adjacent superconducting coil windings (e.g., a first winding (310(1)) and a second winding (310(2))).

[0039] In Figure 3, the reinforcing layer is shown as a single layer. In some embodiments, as shown in Figure 4, the reinforcing layer (420) may include multiple layers (421, 422, 423). In some embodiments, the reinforcing layer may include at least two, at least three, or at least four layers, up to ten, up to eight, up to six, up to five, or up to four layers (including all of these ranges and partial ranges thereof).

[0040] High-strength reinforcing materials can be selected to optimize strength, specific heat, electrical and thermal resistivity, cost, and other properties. Suitable very high-strength reinforcing materials include high-strength steel, superalloys such as Hastelloy, Inconel, and maraging alloys, and high-strength refractory alloys such as hafnium, tantalum, and / or tungsten. These can be combined with materials having high thermal and electrical conductivity, such as aluminum, copper, silver, carbon fiber, or layers thereof.

[0041] In some embodiments, the thickness of at least one reinforcing layer (e.g., a first thickness t1(331) and a second thickness t2(332)) can be constant. In other embodiments, the thickness of the reinforcing layer can be varied across the cross-section of the coil to match the required distribution of strength and heat capacity while minimizing the cross-sectional area and cost of the coil. For example, the thickness of at least one reinforcing layer at a first location (e.g., the first thickness t1(331)) may differ from the thickness of at least one reinforcing layer at a second location (e.g., the second thickness t2(332)). The variation in thickness can be continuous, for example, by uniformly or variably tapering the reinforcing material, or by providing relatively short thickness inclines between separate levels to vary between a set of separate thicknesses. Referring to Figure 5, an incline (501) in the winding direction (502) is shown in the reinforcing layer. This incline may generally be shorter than the length of one turn. As shown in the figure, the reinforcing layer may have a width w(510). The length l(520) of the inclined section is generally relatively short, but long enough so that the change in thickness does not damage the superconducting layer placed directly above the inclined section. For example, if there is a mandrel of any shape and size and the reinforcing layer is intended to wrap around the mandrel at least 360 degrees (e.g., at least one full turn), the length of the inclined section can be 0.25 to 1 turn. The length of the inclined section may be less than 1 turn. The length of the inclined section can be at least 0.25 turns, at least 0.3 turns, at least 0.35 turns, at least 0.4 turns, at least 0.45 turns, or at least 0.5 turns, and can be at most 1 turn or less, 0.9 turns or less, 0.8 turns or less, 0.7 turns or less, or 6 turns or less (including all of these ranges and their sub-ranges).

[0042] The dimensions of the co-wound reinforcing layer can be appropriately varied depending on the coil shape, the materials used, the size and shape of the winding pack, the magnetic field strength, and the magnetic energy to be stored. Any suitable width can be narrower or wider than the width of the superconducting wire, tape, or cable. In the case of layer-wound coils, the width of the reinforcing material may be the same as or wider than the width of the layer. For large-diameter, high-field coils where the maximum magnetic field on the inside of the winding pack (smaller radius side) is more than three times that of the magnetic field at the center of the coil, the thickness of the co-wound reinforcing material can be 2 to 3 times the thickness of the superconductor. In the low-field region near the outside of the winding pack (larger radius side), the thickness of the co-wound reinforcing material tends to be about the same as or thinner than the thickness of the superconductor. This is applicable to both pancake-wound and layer-wound coils.

[0043] In some embodiments, at least a portion (520) of the co-wound reinforcement layer may include a resistive or conductive coating to promote or inhibit the conduction of current around the structural reinforcement and to promote or inhibit the penetration of heat into the reinforcement. In some embodiments, a portion (521) of the co-wound reinforcement layer may not have a resistive or conductive coating. Referring to Figure 4, in some embodiments, the resistive or conductive coating may be a surface (424) adjacent to the superconducting winding (410). In some embodiments, the resistive or conductive coating may be a surface (425) not adjacent to the superconducting winding. When a resistive coating is used, the resistive coating may be a silicon, germanium, silicon carbide bonding layer, or a boronation or carbide surface treatment.

[0044] Referring to Figure 6A, in the second modified example, multiple coil windings can be wound as helical layers (610(1), ..., 610(n)) around a curved surface about a central axis (101), and at least one co-winding reinforcing layer (620(1), ..., 620(n)) is placed between at least two adjacent superconducting coil windings or layers of superconducting coil windings (here, between the first layer 610(1~n) and the second layer 611(1~n)). In Figure 6A, the mandrel defines the curved surface, and the helical layer of superconductor can be wound helically around the mandrel, for example, starting from a first end (601) or its vicinity, and ending at a second end (620). The first superconductor layer may then be bonded to a reinforcing layer, which may, for example, start from a second end (620) and be wound down toward the first end (601) in a helical pattern. This process can be repeated as needed. In Figure 6B, instead of the reinforcing layer being wound in a helical pattern, the reinforcing layer may simply extend from one end to the other, forming a layer between the first helical layer of the superconductor (e.g., layer (610(1~n))) and the second helical layer of the superconductor (e.g., layer 611(1~n)).

[0045] In some embodiments, the radial width or thickness t3(631) of each reinforcing layer may be the same. In some embodiments, the radial width or thickness t3(631) of the first set of layers may vary as disclosed herein.

[0046] The coil windings and the reinforcing layer should not contain organic insulators.

[0047] Referring to Figure 7, the magnetic field lines of the solenoid are shown, and the enlarged section indicates the direction of the shielding current within the solenoid (for example, the alternating portion within the solenoid between the first part (701) rotating in the first direction and the second part (702) rotating in the second direction) and the radial Lorentz force. As can be seen from the figure, the Lorentz force is directed radially inward for the shielding current in the first direction (for example, the first part (701)) and radially outward for the shielding current in the second direction (for example, the second part (702)).

[0048] Referring to Figure 8, the plot shows the stress distribution in a cross-section of a solenoid winding pack having a co-wound structural reinforcement as disclosed herein.

[0049] Figure 9 is an image showing a 3D model of the magnet assembly as disclosed herein, and Figure 10 is an image showing a prototype magnet assembly.

[0050] Except for the arrangement of the layers, the coil winding, and the reinforcing layers, and its modifications are the same as the first modification and can be configured as disclosed herein. For example, each reinforcing layer may be a single layer or a multilayer, and the thickness of the reinforcing layers may be constant or vary.

[0051] Co-winding material can be selected, for example, to control the thermal capacity of the winding pack for coil quench protection (uniform energy release), to adjust the contact resistance between the conductor and the co-winding material for passive protection in NI (non-insulated) coils, and / or to provide structural reinforcement to ensure control of mechanical strain in the superconductor within the winding pack.

[0052] For example, with respect to the coils disclosed herein, the co-winding reinforcement can be adjusted and / or designed to provide a desired inter-turn electrical contact resistance in an all-metal coil. In the case of large-diameter coils, the contact area between adjacent turns is very large, and as a result, the inter-turn resistance may be very low. This resistance is preferably low enough so that the current can easily bypass any normal region by flowing radially between the windings, thereby providing quench protection. Higher resistance values ​​can be used to increase the operating voltage of the coil and shorten the excitation time. Quench stability can be quantitatively evaluated and optimized. The inter-turn resistance can be adjusted by the selection of the reinforcement, or by incorporating conductive or resistive coatings such as silicon, germanium, silicon carbide, or copper tight bonding layers into the reinforcement, or by boronation or carbide surface treatment.

[0053] Superconducting reinforcement can be incorporated into coil windings in several ways, including the following: - As a co-wound layer connected to the superconductor by friction, winding tension, and clamping force. - Before winding the coil, bonding to the superconductor by soldering, brazing, diffusion bonding, or the use of conductive adhesive. - By joining the superconductor to the rest of the coil pack by soldering, brazing, diffusion bonding, or adhesive after the coil has been wound, as described in the appendix.

[0054] To verify the stress and thermal properties, numerous prototype superconducting coil windings were designed, fabricated, and tested using a continuous winding method for stacking double pancake coils.

[0055] The approach of this disclosure is constrained by the properties of reinforcing materials, particularly readily available reinforcing materials. The reinforcing materials should have (1) a high Young's modulus for structural reinforcement to minimize mechanical strain within the coil winding pack; (2) high thermal capacity and thermal conductivity to function as a heat sink as part of the cold mass (non-superconducting portion) within the winding pack for coil quench protection; and (3) moderate electrical conductivity to allow winding current to move between layers and avoid the normal (non-superconducting) region.

[0056] If necessary, the electrical conductivity of the reinforcing material can be increased by applying a layer of copper or other highly conductive material. This can be done by plating, lamination, or other physical deposition processes.

[0057] The approach described herein is particularly useful in high-field, large-diameter fusion energy magnets, allowing design analysis to be performed to identify the necessary balance between stress and thermal management during HTS coil quenching. Referring to Figure 11, a side view of a non-circular toroidal magnetic field coil (1100) is shown. The coil can be of any suitable size, such as a 0.8m coil, a 2.4m coil, or a 4m coil.

[0058] A cross-sectional view of the toroidal magnetic field coil reveals, as disclosed herein, that the magnet has multiple superconducting layers (1110) and multiple reinforcing layers (1120, 1121, 1122). As shown in Figure 11, each reinforcing layer is positioned between two adjacent superconducting windings or layers, and for example, an inner structure (1130) and an outer structure (1131) may be present. As illustrated, the further inward the magnetic field coil is (e.g., the inside of a "D" shaped coil), the greater the thickness of the reinforcing layer (e.g., reinforcing layer (1120)) may be than the thickness on the outside of the magnetic field coil. Figure 11 shows the change in thickness of one turn (1121) of a reinforcing layer from the next turn (1122). In a preferred embodiment, the winding is coiled in the z direction as shown in Figure 11 (e.g., winding the shape clockwise as indicated by arrow (1103)).

[0059] Figure 12 shows a set of toroidal magnetic field coils (1200) (top view) arranged to form a toroidal array that can be used, for example, in a tokamak. As is well known in the art, the toroidal magnetic field coil has a first part (1101) intended to face inward toward the toroidal array and a second part (1102) intended to face outward toward away from the toroidal array. As can be easily understood, in addition to the toroidal magnetic field coil, one or more poloidal magnetic field magnets (1210), a central solenoid (1220), etc., may be arranged as needed. The specific design arrangement may vary as needed.

[0060] In the case of toroidal field coils, the conductors can be pancake windings or layered windings by the winding method of this disclosure for quench protection, which has the flexibility to adjust / modify thermal, electrical, and mechanical effects by controlling the winding material, thickness, and winding tension. The scalability of toroidal field coils can be addressed by adjusting the winding by selecting material properties, thickness, and cold mass distribution within the winding pack to achieve optimal thermal, structural, and electrical effects from the standpoint of quench protection.

[0061] The approach described herein is also beneficial for low-cost superconducting magnetic energy storage.

[0062] Therefore, in various embodiments, a method for constructing a superconducting electromagnet for structural reinforcement and quench protection can be provided. This method generally involves forming an all-metal winding (1310) by joining (1312) at least one co-wound reinforcing layer as disclosed herein to a superconducting coil as disclosed herein, and embedding (1314) the at least one co-wound reinforcing layer between at least two windings of the superconducting coil. These steps can be performed in any order, and it is possible to join and then embed, or embed and then join.

[0063] At least one co-wound reinforcing layer can be joined to at least two windings of a superconducting coil in various ways. For example, the reinforcing layer can be joined by friction, winding tension, and clamping force. The reinforcing layer can be joined by soldering, brazing, diffusion bonding, welding, and conductive adhesive. At least one co-wound reinforcing layer can be joined to at least two windings of a superconducting coil by soldering, brazing, diffusion bonding, or adhesive bonding the co-wound reinforcing layer to the superconducting material and the rest of the coil pack after the superconducting coil has been wound.

[0064] This method may include adjusting one or more co-wound reinforcing layers (1316) to provide the desired inter-turn electrical contact resistance in the all-metal coil. Again, this can be done in any order relative to the joining and embedding, before, after, or during the joining and embedding.

[0065] This method may include designing a coil (1320). This may include selecting at least one co-wound reinforcing layer (or, if the co-wound reinforcing layer is made of multiple layers, at least one of those layers) to optimize one or more properties of the reinforcing layer, such as strength, specific heat, electrical conductivity, thermal conductivity and / or cost (1322). Computer-based models for such design work are well known in the art.

[0066] The method may include determining one or more thicknesses of at least one co-wound reinforcing layer to match a desired distribution of strength, heat capacity, electrical conductivity and thermal conductivity (1324).

[0067] The method may include configuring (1326) a material or structure for at least one co-wound reinforcing layer to achieve a desired inter-turn electrical or thermal resistance of a superconducting coil. For example, the inter-turn resistance is adjusted by applying a resistive or conductive coating to at least one co-wound reinforcing layer. As understood, this configuration may be designed in a configuration stage (e.g., configuration (1326)) and performed in a tuning stage (e.g., tuning (1316)). Any suitable resistive or conductive coating may be used as disclosed herein. For example, a conductive copper coating may be suitable, or a resistive boronation surface treatment or other surface treatment may be desirable.

[0068] In particular, the method of this disclosure can also be used for winding large NMR and MRI coils for commercial applications (90% of the current commercial superconducting magnet market). The approach of this disclosure is especially beneficial for the commercial use of HTS MRI coils, enabling the construction of low-cost, cryogenic coolant-free magnets while maintaining reliable operation.

[0069] In high-field, large-diameter magnet applications, methods combining stress control, coil quench protection, and / or thermal management are not known in academic or patent literature. Various solutions have been attempted over several decades, but no solution has been found, resulting in failures in some large fusion HTS coils.

Claims

1. It is a superconducting coil, A plurality of coil windings made of a superconducting material that define a conductive channel having an inlet and an outlet, wherein the plurality of coil windings are wound spirally around a curved surface about a central axis, or wound as spiral layers around a curved surface about a central axis, Includes, One or more or all of the plurality of coil windings are operably joined to at least one co-winding reinforcement layer, A superconducting coil in which the at least one co-wound reinforcing layer is disposed between at least two adjacent superconducting coil windings or multiple layers of superconducting coil windings.

2. The superconducting coil according to claim 1, wherein the plurality of coil windings are wound spirally around a curved surface about a central axis, and at least one co-wound reinforcing layer is disposed between at least two adjacent superconducting coil windings.

3. The superconducting coil according to claim 1, wherein the plurality of coil windings are wound as helical layers around a curved surface about a central axis, and at least one co-wound reinforcing layer is disposed between at least two adjacent superconducting coil windings.

4. The superconducting coil according to claim 1, wherein the plurality of coil windings are wound as helical layers around a curved surface about a central axis, and at least one co-winding reinforcing layer is disposed between at least two adjacent layers of the superconducting coil windings.

5. The superconducting coil according to any one of claims 1 to 4, wherein the at least one co-wound reinforcing layer is joined to the at least two adjacent superconducting windings by friction, winding tension, and clamping force.

6. The superconducting coil according to any one of claims 1 to 4, wherein the at least one co-wound reinforcing layer is joined to the at least two superconducting windings by one of soldering, brazing, diffusion bonding, welding and conductive adhesive.

7. A superconducting coil according to any one of claims 1 to 4, wherein the at least one co-wound reinforcing layer is joined to the at least two windings by soldering, brazing, diffusion bonding, or adhesive after the coil has been wound.

8. The superconducting coil according to any one of claims 1 to 7, wherein the at least one co-wound reinforcing layer comprises a single layer.

9. The superconducting coil according to any one of claims 1 to 7, wherein the at least one co-wound reinforcing layer comprises a plurality of layers.

10. The superconducting coil according to any one of claims 1 to 9, wherein the thickness of the at least one co-wound reinforcing layer is constant.

11. A superconducting coil according to any one of claims 1 to 10, wherein the thickness of the at least one co-wound reinforcing layer at the first position is different from the thickness of the at least one co-wound reinforcing layer at the second position.

12. The superconducting coil according to claim 11, wherein the thickness of the at least one reinforcing layer is continuously changed by uniform or variable tapering of the at least one reinforcing layer.

13. The superconducting coil according to claim 11, wherein the thickness of the co-wound reinforcing layer varies between a set of separate thicknesses with inclined portions between separate levels, and the inclined portions have a length of less than one turn of the superconductor around the coil.

14. The superconducting coil according to any one of claims 1 to 13, wherein at least a portion of the co-wound reinforcing layer includes a resistive or conductive coating.

15. The superconducting coil according to claim 14, wherein the resistive coating is a surface treatment.

16. The superconducting coil according to claim 14, wherein the resistive coating is a tightly bonded coating.

17. The superconducting coil according to claim 14, wherein the resistive coating is boronized or carbonized.

18. The superconducting coil according to any one of claims 1 to 17, wherein the at least one co-wound reinforcing layer comprises aluminum, copper, silver, carbon, silicon, germanium and / or silicon carbide.

19. The superconducting coil according to any one of claims 1 to 18, wherein the at least one co-wound reinforcing layer comprises high-strength steel, superalloy, maraging alloy, or high-strength refractory alloy containing molybdenum, hafnium, tantalum and / or tungsten.

20. The superconducting coil according to any one of claims 1 to 19, wherein the superconducting material is in the form of a wire, a tape, and / or a cable including embedded wires and / or tape.

21. A method for constructing a superconducting electromagnet for structural reinforcement and quench protection, Joining at least one co-wound reinforcing layer to the superconducting coil; and The at least one co-wound reinforcing layer is embedded between at least two windings of the superconducting coil. A method that includes this.

22. The method according to claim 21, wherein the at least one co-wound reinforcing layer is joined to the at least two windings of the superconducting coil by one of friction, winding tension, and clamping force.

23. The method according to claim 21, wherein the at least one co-wound reinforcing layer is joined to the at least two windings of the superconducting coil by one of soldering, brazing, diffusion bonding, welding and conductive adhesive.

24. The method according to claim 21, wherein the at least one co-wound reinforcing layer is joined to the at least two windings of the superconducting coil by soldering, brazing, diffusion bonding or adhesion after the superconducting coil has been wound.

25. The method according to any one of claims 21 to 24, further comprising adjusting the at least one co-wound reinforcing layer to provide a desired inter-turn electrical contact resistance in an all-metal coil.

26. The method according to any one of claims 21 to 25, further comprising selecting the at least one co-wound reinforcing layer to optimize strength, specific heat, electrical conductivity, thermal conductivity and / or cost.

27. The method according to any one of claims 21 to 26, wherein the at least one co-wound reinforcing layer is made from a plurality of layers.

28. The method according to claim 27, further comprising selecting at least one of the plurality of layers to optimize strength, specific heat, electrical conductivity, thermal conductivity and / or cost.

29. The method according to any one of claims 21 to 28, further comprising determining the thickness of one or more of the at least one co-wound reinforcing layers to conform to a desired distribution of strength, heat capacity, electrical conductivity and thermal conductivity.

30. The method according to any one of claims 21 to 29, further comprising configuring the material or structure of the at least one co-wound reinforcing layer to achieve the desired electrical or thermal resistance between turns of the superconducting coil.

31. The method according to claim 30, wherein the resistance between turns is adjusted by applying a resistive or conductive coating to at least one co-wound reinforcing layer.

32. The method according to claim 31, wherein the resistive coating is a surface treatment.

33. The method according to claim 31, wherein the resistive coating is an adhesive bonding coating.

34. The method according to claim 31, wherein the resistant coating is boronized or carbonized.

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