Coupling systems for stacked-plate non-insulated superconducting magnets.

Abstract

A scheme for joint geometry and placement in superconducting magnets is described. According to some embodiments, joints can be realized in modular components of superconducting magnets, such as plates that include helical superconducting paths, where the joints provide an electrically conductive connection between the superconducting paths of adjacent plates. The joints can be installed and bonded to a component (e.g., a plate) after fabrication of the component, thereby providing freedom in the design of both the joints and the component. In at least some cases, the joints can be arranged to be flush with a surface of the component after installation within the component, such that adjacent instances of the component can be stacked flush with each other, thereby bringing the joints from adjacent components into intimate contact with each other.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 63 / 143,189, filed January 29, 2021, entitled "Joint Schemes for Stacked Plate, Non-Insulated Superconducting Magnets," which is hereby incorporated by reference in its entirety. [Background technology]

[0002]

[0002] A superconductor is a material that has no electrical resistance to electric current (is "superconducting") below some critical temperature. For many superconductors, the critical temperature is below 30°K, so that operation of these materials in the superconducting state requires significant cooling, such as can be achieved with liquid or supercritical helium.

[0003]

[0003] High field magnets are often constructed from superconductors due to their ability to carry high currents without resistance. Such magnets can illustratively carry currents greater than 5 kA. Summary of the Invention [Means for solving the problem]

[0004]

[0004] According to some aspects, a magnet is provided comprising a plurality of plates arranged in a stack including a first plate and a second plate, wherein the first plate comprises a first conductive path, at least a portion of the first conductive path being a spiral path, the first conductive path comprising a high temperature superconductor (HTS) material, and a first conductive joint arranged inside or outside the spiral path of the first conductive path, the first conductive joint being electrically coupled to the HTS material of the first conductive path, and the second plate is arranged next to the first plate in the stack and comprises a second conductive path comprising an HTS material, and a second conductive joint arranged in close proximity to and electrically coupled to the first conductive joint, the second conductive joint being electrically coupled to the HTS material of the second conductive path.

[0005] The foregoing apparatus and method embodiments may be realized by any suitable combination of the aspects, features, and acts described above or described in more detail below. These and other aspects, embodiments, and features of the present teachings may be more fully understood from the following description taken in conjunction with the accompanying drawings.

[0006] Various aspects and embodiments will be described with reference to the following figures. It should be understood that the figures are not necessarily drawn to scale. In the figures, identical or nearly identical components illustrated in various figures may be represented by like numerals. For purposes of clarity, every component may not be labeled in every figure. [Brief explanation of the drawings]

[0007] [Figure 1A]

[0007] FIG. 1 is a cross-sectional view of a portion of an exemplary plate suitable for use in a stacked-plate superconducting magnet, according to some embodiments. [Figure 1B]

[0008] 1A-1C are cross-sectional views of a portion of an exemplary plate suitable for use in a stacked plate superconducting magnet with alternative joint designs, according to some embodiments. [Figure 1C]

[0009] FIG. 10 is a cross-sectional view of a portion of an exemplary plate suitable for use in a stacked plate superconducting magnet with a second alternative joint design, according to some embodiments. [Figure 2]

[0010] FIG. 2 is a cross-sectional view of two exemplary plates in a stacked-plate superconducting magnet, according to some embodiments. [Figure 3A]

[0011] 1 is a cross-sectional view of adjacent joints in a superconducting magnet, according to some embodiments. [Figure 3B]

[0012] 3B depicts the magnet shown in FIG. 3A with a superconductor disposed within the conducting channel of the joint, according to some embodiments. [Figure 4]

[0013] 1 is a cross-sectional view of adjacent joints in a superconducting magnet, according to some embodiments. [Figure 5A]

[0014] FIG. 1 depicts a top perspective view of a base plate for a stacked plate superconducting magnet, according to some embodiments. [Figure 5B] FIG. 1 depicts a top perspective view of a base plate for a stacked plate superconducting magnet, according to some embodiments. [Figure 6]

[0015] FIG. 1 is a cross-sectional view of a superconducting magnet with multiple plates with joints on the inner and outer sides, according to some embodiments. [Figure 7]

[0016] 1 is a cross-sectional view of a superconducting magnet comprising multiple plates mirrored about a central plane, according to some embodiments. FIG. [Figure 8]

[0017] 1 is a three-dimensional graphic of a fusion power plant with a cutaway portion illustrating various components of the power plant, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0008]

[0018] High-field superconducting magnets often comprise multiple electrically insulated windings of superconductor grouped in a multi-layer arrangement. When the superconductor is cooled below its critical temperature (the temperature below which the material's electrical resistivity drops to zero), electrical current can travel through the superconducting path without losses that would normally occur due to electrical resistance.

[0009]

[0019] Superconducting magnets, and / or the systems to which they are coupled, may include current paths made from non-superconducting conductors (also referred to as "normal conductors"). By way of illustration, the junctions between the superconductors in a magnet and the power supply may comprise normal conductors. In other cases, there may be connections between regions of superconductor within a magnet to aid in the construction of the magnet. Interconnections to and / or within a superconducting magnet are sometimes referred to as "joints." The joints may comprise normal conductors, as in the example above, but in other cases may be interconnections between adjacent regions of superconductor.

[0010]

[0020] In general, it is desirable for joints in superconducting magnets to have several attributes. First, the electrical resistivity of the joint should be as low as possible because current flowing through the joint will cause Joule heating of the joint, and superconducting magnets are operated at low temperatures. Second, the joint should be mechanically robust. During operation, a superconducting magnet can generate large forces (e.g., Lorentz forces) within the structure of the superconducting magnet, which can result in the application of forces (e.g., compressive forces) to the joint and to other parts of the structure. For this reason, joints in superconducting magnets can be considered "electromechanical" structures rather than simply electrical conductors. Third, it is desirable for joints in superconducting magnets to be easy to manufacture. Fourth, it is desirable for the joints to occupy a relatively small amount of space (and ideally minimal space) in the superconducting magnet so that more space is available for containing the superconductor within the magnet.

[0011]

[0021] Conventional superconducting magnet joints generally rely on special preparation of the superconductor so that the superconducting coils can be coupled together. As noted above, it is desirable for the joint to have low electrical resistance, so directly connecting different regions of the superconductor is one way to meet this goal. However, such approaches can be extremely complicated to fabricate and prone to error. Illustratively, adjacent regions of the superconductor must be measured and cut so that they can be in intimate contact with each other when coupled, while having the same contact resistance to ensure uniform current distribution within the joint. These approaches, moreover, can produce fixed assemblies once constructed; i.e., once adjacent regions of the superconductor are attached to each other, it can be difficult or impossible to unattach the joint without damaging or destroying the joint.

[0012]

[0022] The inventors recognize and understand joint designs that utilize normal conductors (i.e., non-superconductors). The joint designs can be implemented in modular components of superconducting magnets, such as plates containing helical superconducting paths, and the joints described herein provide an electrically conductive connection between the superconducting paths of adjacent modular components (e.g., between adjacent plates in a stack of plates). The joints can be installed and coupled to a component (e.g., a plate) after fabrication of the component, thereby providing freedom in the design of both the joint and the component. In at least some cases, the joints can be arranged to be flush with a surface of the component after installation within the component, such that adjacent instances of the component can be stacked flush with each other, thereby bringing the joints from adjacent components into intimate contact with each other. Additionally, the design may allow components to be fabricated with joints before the components are joined together, thereby allowing for a flexible, modular, and convenient fabrication process.

[0013]

[0023] 1A is a cross-section of a portion of an exemplary plate suitable for use in a stacked-plate superconducting magnet, according to some embodiments. In the example of FIG. 1, plate 100 comprises a base plate material 110 in which conductive paths 112 are formed (e.g., by conventional machining processes, by additive and / or subtractive processes, etc.). To create a magnet, superconductors can be inserted into the conductive paths of base plate 110. Conductive paths 112 can comprise channels, grooves, and / or any other spaces into or over which superconductors can be disposed.

[0014]

[0024] In the example of FIG. 1A , the conductive path may be a curved path, such as, but not limited to, a spiral path or multiple concentric circular paths, where successive turns of the path are within the previous turn. The outer portion of the conductive path is coupled to a joint 115, which comprises or consists of a normal conductor, such as copper. The joint 115 comprises a conductive path 116, which is an interior space (e.g., a channel) within the joint, into which the superconductor, which will be inserted into the conductive path 112, may be inserted. Thus, when the joint 115 is installed, disposed, or otherwise provided within the base plate 110, the conductive path 112 and the conductive path 116 may be arranged adjacent to each other to form a continuous path. A superconductor may thus be arranged within the path formed by the combination of the conductive paths 112 and 116.

[0015]

[0025] According to some embodiments, adjacent instances of plates 100 (or instances of similar plates, examples of which are described below) can be arranged so that the plate joints 115 electrically couple to one another. As a result, the superconductor in the conductive path 112 can be arranged in multiple turns within one plate, with one end of the superconductor electrically coupled to a joint 115 (e.g., terminated at joint 115), which couples to a joint in another plate, which couples to another superconductor within that plate, and so on. In this manner, a stack of plates 100 can be arranged with multiple regions of superconductor to form a continuous current path through the stack, with the joints providing a current path across adjacent plates. In some embodiments, this current path can comprise an alternating sequence of inward and outward spirals, with each plate configured such that the conductive path is either an inward spiral path or an outward spiral path. In this case, joint 115 may be arranged on the inside of the spiral or on the outside of the spiral. In some embodiments, plate 100 may include joint 115 on the outside of conductive pathway 112 and a second joint on the inside of the conductive pathway, the two joints arranged to be exposed on opposite faces of the plate, thereby facilitating connection to adjacent plates on the outside of the conductive pathway on one side of the plate and on the inside of the conductive pathway on the other side of the plate.

[0016]

[0026] According to some embodiments, base plate 110 may comprise or consist of a high mechanical strength material, such as, but not limited to, steel, Inconel®, Nitronic® 40, Nitronic® 50, Incoloy®, or combinations thereof. In some embodiments, base plate 110 may be plated with a metal such as nickel to aid in the adhesion of other components to the plate, including solder, as described below.

[0017]

[0027] In the example of FIG. 1A, the conductive path 112 is shown to be on a first surface of the base plate 110 (here illustrated as the outer lower surface of the base plate 110), but it will be understood that the current path may be arranged in any suitable location within the plate, including within the interior of the plate and / or on the outer upper surface of the plate 110.

[0018]

[0028] According to some embodiments, the joints 115 may comprise or consist of copper. In some embodiments, the joints may be mechanically coupled to the base plate 110 by bolts or other fasteners. In some embodiments, the bolts may provide some amount of electrical coupling between the base plate and the joints. Additionally or alternatively, the joints may be coupled to the base plate 110 by other means, such as by attaching the joints to the base plate with solder, brazing or welding the joints to the plate. Solder disposed between the joints and the base plate and mechanically coupling the two together may also provide an electrical coupling between the two. Thus, electrical continuity between the plates may be increased by adding electrically conductive material around the joints, for example, by soldering the periphery of the joints.

[0019]

[0029] The geometry of the joint 115, according to some embodiments, may allow the joint 115 to be inserted into the base plate 110 subsequent to the plate being fabricated. In this case, it may be advantageous to mechanically couple (i.e., removably couple) the joint to the plate rather than fixedly coupling (e.g., by brazing or welding) the joint to the plate. In some embodiments, following installation of the joint 115 in the base plate 110, molten solder may be introduced into the plate to fill any gaps between the joint and the plate. In some cases, a mold solder process may also be introduced into the conductive vias 112 to fill any gaps between the base plate 110 and the superconductor introduced into the vias.

[0020]

[0030] According to some embodiments, prior to installation of the fitting within the plate 110, some or all of the fitting 115 (e.g., the inside of the conductive channel 116 and / or the outside of the fitting that will contact the base plate 110) may be pre-tinned with a metal (e.g., PbSn solder, plated with silver, etc.) to promote a good bond (e.g., mechanical and / or electrical connection) between the fitting and a subsequently deposited solder. The fitting may be inserted into (or otherwise provided within) the plate and, optionally, mounted to (e.g., fastened to) the plate by one or more mechanical fasteners, such as by bolts. A conductive material may then be deposited into the groove into which the fitting was inserted (or otherwise provided) by a vacuum pressure impregnation (VPI) process. Such a process may include one or more of the following steps: cleaning the open space in the plate using an acidic solution followed by a water rinse; evacuating the space from within the plate; purging the space with an inert gas; depositing flux into the space so that it covers the joints 115; draining any excess flux from the plate; heating at least a portion of the plate to a temperature below, at, or above a temperature at which the alloy to be deposited will melt; and flowing a molten alloy (e.g., PbSn solder) into the plate.

[0021]

[0031] According to some embodiments, the base plate 110 may include one or more through-holes (i.e., one or more holes extending from a first surface of the plate to a second, opposing surface of the plate—not shown in FIG. 1A ) for attaching the plate to other plates and / or other structures. In some cases, the through-holes may include internal threads to facilitate the insertion of threaded mechanical fasteners, such as screws or bolts, into or through the plate.

[0022]

[0032] According to some embodiments, baseplate 110 may include one or more cooling channels for delivering coolant to superconductors disposed in conduction channels 112. The cooling channels may be disposed proximate to conduction channels 112 and / or may be disposed anywhere else in plate 100. In some cases, joints 115 may have a geometry such that after the joint is inserted into the baseplate, open areas remain between the joint and baseplate 110. Such open areas may be used as cooling channels. The joint designs described herein may thus allow for flexibility in coolant channel design within the plate.

[0023]

[0033] According to some embodiments, joint 115 can be machined to have a smooth upper surface—i.e., the exposed surface that will contact another joint in another plate. A smooth surface can reduce contact resistance (i.e., reduce electrical resistance between two mechanical structures in contact with each other). In this example, the smooth surface can reduce contact resistance between joint 115 and a joint in another plate, which in turn leads to less Joule heating of the joint and / or nearby materials.

[0024]

[0034] The example of Figure 1A depicts a plate that may be suitable for use in a non-insulated (NI) magnet design (further referred to as a no-insulation (NI) magnet) in which adjacent superconducting turns of the magnet are not insulated from one another but instead are separated by a normal conductor (i.e., not a superconductor). In this example, the normal conductor is base plate 110. When the magnet is operating below the critical temperature of the superconductor, current will flow through the superconductor and not across the turns because the superconductor has zero resistance compared to the finite resistance of the conductor between the turns.

[0025]

[0035] However, during a quench, at least one or more portions of the superconductor may be in a "normal" (non-superconducting) state (i.e., at least one or more portions of the superconductor have a finite resistance rather than the zero resistance characteristic of superconductors). At least one or more portions of the superconductor that have normal resistance are sometimes referred to as the "normal zone" of the superconductor. When the normal zone appears, at least some zero-resistance current paths no longer exist, which causes current to flow through the normal zone and / or between turns, with the balance of current flow between these paths depending on the relative resistances of the paths. By diverting at least some current from the superconducting material in this manner when the superconducting material is normally conducting, NI magnets, and in particular non-insulated high temperature superconductor (NI-HTS) magnets (NI magnets with HTS), can therefore, in principle, be passively protected against quench damage without the need to continuously monitor for quench events and / or actively engage external quench protection mechanisms.

[0026]

[0036] Figure 1B is a cross-section of a portion of an exemplary plate suitable for use in a stacked-plate superconducting magnet with an alternative joint design, according to some embodiments. Figure 1B illustrates plate 101 with the same base plate 110 (and further including the same conductive pathway 112) as in the example of Figure 1A, but with a joint 125 having a different geometry relative to joint 115 shown in Figure 1A. Aside from the different geometry for the upper surface of joint 125, all of the comments above regarding Figure 1A also apply to Figure 1B, with conductive pathway 126 being a pathway within joint 125 that may be arranged in proximity to conductive pathway 112, just as for conductive pathway 116 in the example of Figure 1A.

[0027]

[0037] According to some embodiments, the upper surface of joint 125 may not be positioned flush with the upper surface of base plate 110, but may include a notch or other feature designed to mate with a complementary feature in a joint of an adjacent plate. In the example of FIG. 1B , by way of illustration, joint 125 includes a portion that protrudes above the upper surface of base plate 110, with the remainder of the joint being flush with the upper surface of the base plate. Another plate may be fabricated that includes a joint with a portion that is recessed below the upper surface of base plate 110, with the remainder of the joint being flush with the upper surface of the base plate. As a result, these joints may mate together when the plates are positioned adjacent to one another. The approach of FIG. 1B may enhance or simplify alignment of adjacent plates by increasing the contact area between the two plates compared to the example of FIG. 1A , and / or enable a more robust electrical connection between the two joints. In some embodiments, the height of the protrusion of fitting 125 may be less than 0.02 inches (e.g., 0.015 inches) above the face of fitting 125. It should be understood that the protruding portion may be provided having any regular or irregular geometric shape. The shape of the protruding portion may be selected to suit the needs of a particular application.

[0028]

[0038] 1C is a cross-section of a portion of an exemplary plate suitable for use in a stacked plate superconducting magnet with a second alternative joint design, according to some embodiments. FIG. 1C illustrates plate 102 with a base plate 130 having a conductive path 132 formed therein. The base plate further includes a channel into which a joint 135 is inserted. Joint 135 includes a conductive channel 136 and is mechanically coupled to base plate 110 by a bolt 137. Joint 135 thus includes a through-hole for the bolt, and base plate 130 includes a hole that aligns with the through-hole in the joint for insertion of the bolt.

[0029]

[0039] The comments above regarding Figure 1A may also apply to the example of Figure 1C with respect to joint 135, base plate 130, conductive pathway 132, and conductive pathway 136, and with respect to joint 105, base plate 110, conductive pathway 112, and conductive pathway 116, respectively. However, it may be pointed out that in the example of Figure 1C, conductive pathways 132 and 136 are arranged on the uppermost surfaces of base plate 130 and joint 135, respectively. This location of the pathways in the base plate and joint may simplify the insertion of superconductors into the pathways, as compared to the example of Figures 1A-1B, because in Figure 1C, the pathways are exposed at the top of the plate after installation of the joints into the base plate.

[0030]

[0040] Figure 2 is a cross section of two exemplary plates in a stacked-plate superconducting magnet, according to some embodiments. The example of Figure 2 depicts magnet 201 comprising plate 100 shown in Figure 1A in contact with second plate 200, which includes conductive path 212 in base plate 210 and joint 215 with conductive path 216. Like conductive paths 116 and 112 in the example of plate 100, conductive path 216 in joint 215 can be arranged in close proximity to conductive path 212.

[0031]

[0041] According to some embodiments, a first superconductor may be disposed in conductive paths 112 and 116, and a second superconductor may be disposed in conductive paths 212 and 216. As a result, during operation at temperatures at which the superconductors are superconducting, the current path of magnet 201 may flow along the first superconductor, through joint 115 to joint 215, and then along the second superconductor. Joints 115 and 215 may be disposed at the inner or outer ends of plates within the magnet, and, as discussed above, regardless of whether the joint depicted in FIG. 2 is disposed at the outer or inner ends of the plates, additional joints may be disposed at opposite ends of the plates.

[0032]

[0042] According to some embodiments, a metal layer may be disposed between joints 115 and 215 to facilitate intimate electrical contact between the joints. The metal may illustratively be a soft metal configured to compress and conform to the surfaces of the joints during assembly of the magnet. In some embodiments, the metal layer may comprise or consist of indium.

[0033]

[0043] FIG. 3A is a cross-section of adjacent joints in a stacked-plate superconducting magnet, according to some embodiments. The example in FIG. 3A depicts an alternative design for the base plate and joints, including a clamp that fastens the plates together. Magnet 300 includes plate 301 and plate 302. Plate 301 includes base plate 310, two portions of which are shown in cross-section in FIG. 3A, and plate 302 includes base plate 320, two portions of which are shown in cross-section in FIG. 3A. Plate 301 includes joint 315, in which conductive channel 316 is arranged. Plate 302 includes joint 325, in which conductive channel 326 is arranged. Plates 301 and 302 further include fasteners 319 and 329, respectively, through which bolts 331 and 332 pass to attach plates 301 and 302 to one another. As noted above, the bolts may be fully or partially threaded to mate with threads provided in one or both of plates 301, 302, or may be threaded to mate with nuts.

[0034]

[0044] According to some embodiments, each plate of magnet 300 can be assembled by inserting a joint into a base plate and, optionally, mechanically attaching the joint to the base plate (e.g., as in the example of FIG. 1C described above). Superconductor can then be inserted into the conductive paths of the base plate (these paths are not shown in the example of FIG. 3A ) and into the conductive paths of each joint (e.g., paths 316 or 326). Optionally, solder can then be deposited into the conductive paths of the base plate and the joints, such as by a VPI process as described above. The stack of plates formed by this method can then be arranged, and the plates can be joined together by fasteners arranged between adjacent pairs of plates (or between three or more plates). Optionally, a layer of soft metal such as indium may be disposed between the joints of adjacent plates in the stack so that when force is applied across the joint-to-joint junction by the fastener, the metal conforms to the joint and provides good electrical contact between the joints.

[0035]

[0045] For illustrative purposes, Figure 3B depicts the stack shown in Figure 3A with superconductors disposed within the conductive channels (visible in Figure 3A) of joints 315 and 325. Specifically, arranged in the conductive path are HTS material 332, lid 336, and intervening conductive material 334 that provides electrical and thermal contact between HTS material 332 and lid 336.

[0036]

[0046] In the example of FIG. 3B , the HTS material is provided as a co-wound stack of HTS tape. According to some embodiments, the HTS 332 can comprise a rare earth barium copper oxide superconductor (REBCO), such as yttrium barium copper oxide (YBCO). In some embodiments, the HTS tape can comprise long, thin strands of HTS material. In embodiments, the strands of HTS material can be provided with cross-sectional dimensions in the range of about 0.001 mm to about 0.1 mm in thickness (or height) and about 1 mm to about 12 mm in width (and with lengths extending into and out of the page in the example of FIG. 3B ). According to some embodiments, each strand of the HTS tape can comprise an HTS material, such as REBCO, in addition to an electrically conductive material (referred to as co-wound). In some embodiments, the electrically conductive material can be disposed on the REBCO. In some embodiments, the electrically conductive material can be a cladding material, such as copper. In some embodiments, the HTS tape may comprise polycrystalline HTS and / or may have a high level of grain orientation.

[0037]

[0047] According to some embodiments, the lid 336 may comprise or consist of copper. According to some embodiments, the conductive material 334 may comprise Pb and / or Sn solder. In some embodiments, the conductive material 334 may comprise a metal having a melting point less than 200°C, where at least 50% by weight of the metal is Pb and / or Sn and at least 0.1% by weight of the metal is Cu. In some embodiments, the conductive material 334 may be solder introduced into the plate by a VPI process as discussed above.

[0038]

[0048] Figure 4 is a cross section of adjacent joints in a superconducting magnet, according to some embodiments, depicting an alternative design to that shown in Figures 3A and 3B, including cooling channels, joint mounting bolts, and chamfers and drains to aid in the VPI process of introducing solder into the plates.

[0039]

[0049] Magnet 400 includes plate 401 and plate 402. Plate 401 includes base plate 410, two portions of which are shown in cross section in FIG. 4A, and plate 402 includes base plate 420, two portions of which are shown in cross section in FIG. 4A. Plates 401 and 402 include joints 415 and 425, respectively, with superconductor 432 disposed within channels within the joints. Plates 401 and 402 further include fasteners 419 and 429, respectively, with bolts 431 and 433 passing through the fasteners to attach plates 401 and 402 to one another. A layer 427 of soft metal, such as indium, is disposed between the joints. The soft metal layer between the joints may create a high degree of contact between the joints (e.g., may fill imperfections in the surfaces of either or both joints to ensure that the surfaces are flush) and may also allow the joint to be easily disassembled and reassembled. In some embodiments, the thickness (e.g., vertically in FIG. 4) of the combination of joint 425 and fastener 429 may be equal to or approximately equal to the thickness of base plate 420.

[0040]

[0050] 4, joints 415 and 425 are configured such that cooling channels 460 are provided between the joints and their respective base plates (and, in the case of plate 402, additionally between the joints and fastener 429). As shown, the geometries of the base plates and joints can be selected to leave suitable channels for coolant between those elements.

[0041]

[0051] 4 includes joint attachment bolts 441 and 442 that attach joint 415 to base plate 410 and joint 425 to base plate 420, respectively. In the example of FIG. 4, joints 415 and 425 can have portions shaped to form or otherwise provide drainage areas 451 and 452, respectively. In this example, joints 415, 425 have chamfer-shaped portions that define (or form) drainage areas 451, 452. Joints 415 and 425 can, of course, also be provided with other shapes (i.e., portions having shapes other than chamfer-shaped) that can define drainage areas 451, 452. In some embodiments, drainage area 451 can be configured to capture excess solder and / or flux that may flow over the surface of the board during a solder deposition process (e.g., the VPI process described above).

[0042]

[0052] 5A and 5B depict top perspective views of a base plate for a stacked-plate superconducting magnet, according to some embodiments. In the example of FIG. 5A, only the base plate is shown, while in FIG. 5B, the same base plate is shown with couplings and superconductors arranged therein.

[0043]

[0053] 5A, base plate 510 includes grooves or recesses 513 and 514 into which fittings can be inserted. The base plate further includes mounting locations 518 and 519 for mounting fittings to the base plate (e.g., the mounting locations can include threaded or non-threaded holes for bolts).

[0044]

[0054] Figure 5B depicts base plate 510 following the insertion of couplings 515 and 525 into the base plate, along with superconductor 532. In the example of Figure 5B, coupling 515 is configured to have an exposed upper conductive surface (e.g., as in the portion of plate 402 shown in Figure 4), while coupling 525 is configured to have an exposed lower conductive surface (e.g., as in the portion of plate 401 shown in Figure 4). Coupling 525 includes bolts 541 that attach the coupling to base plate 510, holes 552 for coupling fasteners to attach the plate to another plate in a magnet, and grooves or recesses 549 for fasteners to be inserted to attach the plate to another plate, as shown in Figure 5B.

[0045]

[0055] FIG. 6 is a cross-section of a superconducting magnet including multiple plates, each including a joint on its inner and outer sides, according to some embodiments. To further illustrate how the joint designs described above can be implemented in a superconducting magnet, FIG. 6 depicts a magnet 600 including several plates, each including an inner joint and an outer joint. In FIG. 6, the uppermost and lowermost plates are cut away, but it will be understood that the illustrated arrangement can be repeated for as many plates as desired or necessary. In magnet 600, each plate includes four turns of superconductor 634, and each pair of adjacent plates is fastened together by fasteners 629 at either the inner or outer ends, with the fastener locations alternating for each successive pair of plates, as shown. A layer of insulating material 641 is disposed between adjacent plates except in the areas where the joints contact one another (although it will be understood that such a layer of insulating material may not be a required feature, as illustratively the example of FIG. 3B does not include such a layer). As shown in FIG. 6, this insulating layer may be provided between adjacent fasteners in each pair of fasteners.

[0046]

[0056] In the example of FIG. 6 , the joint design recesses the fasteners into the joint, so the thickness of the joints plus the fasteners is the same (or approximately the same) as the average thickness of the plates themselves. As a result, all of the inner joints can be arranged on top of each other, and all of the outer joints can be arranged on top of each other, as shown in FIG. 6 . As a result, magnet 600 can be formed from only two unique plates (e.g., so-called A and B plates), with adjacent instances of these plates meeting at the inner joint and at the outer joint. This arrangement can be repeated because, as noted above, the thickness of the joints plus the fasteners can be the same (or approximately the same) as the average thickness of the plates, so the plates can overlap one another. Thus, the joint design techniques described herein make it possible to create magnets with a relatively small number of unique plates (in this example, only two unique plates are required). The joint designs described herein further enable magnets to be made with a relatively small number of overall joint locations, so that a small (and ideally minimal) overall volume of the magnet is devoted to joint volume. Thus, the joint designs described herein result in magnets that are relatively simple to assemble (because there are a relatively small number of unique plates) and have a relatively small volume occupied by joints connecting the magnet plates.

[0047]

[0057] 7 is a cross-section of a superconducting magnet comprising multiple plates mirrored about a mid-plane, according to some embodiments. In some cases, plates with joints as described above may be arranged in a stack mirrored about a mid-plane. Such a stack may include four types of plates, with two types of plates arranged in an alternating fashion on either side of the mid-plane.

[0048]

[0058] As shown in the example of FIG. 7 , plate stack 700 (also referred to as a "winding pack") comprises multiple plates that are mechanically and electrically coupled to one another by the jointing techniques described above. As shown, each plate in stack 700 is coupled to an adjacent plate by an inner joint and an outer joint. As shown in FIG. 7 , stack 700 includes repeated, alternating instances of plates 701 and 702 below the mid-plane and repeated, alternating instances of plates 703 and 704 above the mid-plane. In some embodiments, plates 701 and 702 can be mirror images of plates 703 and 704, respectively.

[0049]

[0059] As in the example of FIG. 6 , the joint design in FIG. 7 recesses the fasteners into the joint, and the thickness of the joint plus the fasteners is the same (or approximately the same) as the average thickness of the plates themselves. As a result, all of the inner joints can be arranged on top of each other, and all of the outer joints can be arranged on top of each other. Furthermore, as in FIG. 6 , the technique illustrated in FIG. 7 makes it possible to create windings with a relatively small number of unique plates (in this example, only four unique plates are required). The joint designs described herein also make it possible to create windings with a relatively small number of overall joint locations, thus devoting a small (and ideally minimal) overall volume of the winding to joint volume. Thus, the joint designs described herein result in windings that are relatively simple to assemble (because there are relatively few unique plates) and have a relatively small volume occupied by joints connecting the winding plates.

[0050]

[0060] In the example of Figure 7, a malleable conductive metal (e.g., indium) may be placed between the plates in the winding to provide good electrical connection between the plates. In this particular example, it is preferred that the malleable metal (e.g., indium) be highly compressible. Suitable compression may be achieved by a fitting described herein (e.g., by a bolt to draw together fasteners (e.g., steel fasteners) around the indium).

[0051]

[0061] FIG. 8 is a three-dimensional graphic of a fusion power plant, with a cutaway portion illustrating various components of the power plant, according to some embodiments. The magnets in the fusion power plant may be formed from a superconductor arrangement as described above. FIG. 8 shows a cross section through the power plant, including magnet coils 814 fabricated from or otherwise including superconducting magnets with plate stacks as discussed and described above, neutron shielding 812, and core region 811. According to some embodiments, magnet coils 814 may be toroidal field coils or form part of toroidal field coils. Magnet coils 813 may be fabricated from or otherwise include superconducting magnets with plate stacks as discussed and described above. According to some embodiments, magnet coils 813 may be or form part of central solenoid and / or other poloidal field solenoid coils.

[0052]

[0062] Those skilled in the art will appreciate other embodiments of the concepts, results, and techniques disclosed herein. It will be understood that superconducting coils constructed according to the concepts and techniques described herein can be useful for a wide variety of applications, including any application in which superconducting material is wound into a coil to form a magnet. By way of illustration, one such application is to conduct nuclear magnetic resonance (NMR) studies, for example, into solid state physics, physiology, or proteins, for which superconducting coils can be wound into magnets. Another application is to perform clinical magnetic resonance imaging (MRI) for medical scanning of organisms or portions of those organisms, for which a small high-field magnet is required. Yet another application is high-field MRI, for which a large-diameter solenoid is required. Yet another application is for performing magnetic studies in physics, chemistry, and materials science. Further applications are in particle accelerators for material processing or interrogation; power generators; medical accelerators for proton therapy, radiation therapy, and generally radiation production; superconducting energy storage; magnetohydrodynamic (MHD) electricity generators; and magnets for material separation, such as mining, semiconductor fabrication, and recycling. The above list of applications is not exhaustive, and it will be understood that there are further applications in which the concepts, processes, and techniques disclosed herein can be put to use without departing from the scope of those concepts, processes, and techniques.

[0053]

[0063] As used herein, "high temperature superconductor" or "HTS" refers to a material that has a critical temperature above 30 K, the temperature below which the electrical resistivity of the material drops to zero.

[0054]

[0064] Illustrative examples of conduction pathway channels are described herein and illustrated in the drawings, it being understood that the particular sizes and shapes of these channels are provided by way of example only, and that no particular cross-sectional shape or size is implied as required or desirable unless otherwise indicated.

[0055]

[0065] Having thus described various aspects of at least one embodiment illustrating the concepts described, it will be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art.

[0056]

[0066] Such alterations, modifications, and improvements are intended to be part of this disclosure and are intended to be within the spirit and scope of the concepts described herein. Moreover, while advantages of the concepts described herein are indicated, it should be understood that not every embodiment of the technology described herein will include every described advantage. Some embodiments may not realize every feature described as advantageous herein, and in some instances, one or more of the described features may be implemented to achieve further embodiments. Thus, the foregoing description and drawings are by way of example only.

[0057]

[0067] Various aspects of the concepts described herein may be used alone, in combination, or in various arrangements not specifically discussed in the above-described embodiments, and therefore are not limited in their application to the details and arrangements of components discussed in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments.

[0058]

[0068] Furthermore, the concepts described herein may be implemented as methods, examples of which are provided. The acts performed as part of the method may be ordered in any suitable manner. Thus, embodiments may be constructed in which acts are performed in an order different from that illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in the exemplary embodiment.

[0059]

[0069] Additionally, some actions are described as being taken by a "user." It should be understood that a "user" need not be a single individual, and that in some embodiments, actions attributable to a "user" may be performed by a group of individuals and / or an individual in combination with a computer-assisted tool or other mechanism.

[0060]

[0070] The use of ordinal terms such as "first," "second," "third," etc. in the claims to modify claim elements does not, by itself, imply any priority, ranking, or order of one claim element relative to another, or the temporal order in which method actions are performed, but is merely used as a marker to distinguish one claim element having a certain name from another element having the same name (but for the use of the ordinal term).

[0061]

[0071] The terms "approximately" and "about" can be used in some embodiments to mean within ±20% of a target value, in some embodiments within ±10% of a target value, in some embodiments within ±5% of a target value, and even in some embodiments within ±2% of a target value. The terms "approximately" and "about" can include the target value. The term "substantially equal" can be used in some embodiments to refer to values ​​that are within ±20% of each other, in some embodiments within ±10% of each other, in some embodiments within ±5% of each other, and even in some embodiments within ±2% of each other.

[0062]

[0072] The term "substantially" may be used to refer to values ​​that are within ±20% of the comparative scale in some embodiments, within ±10%, within ±5%, and even within ±2% in some embodiments. For example, a first direction that is "substantially" orthogonal to a second direction may refer to a first direction that is within ±20% of forming a 90° angle with the second direction in some embodiments, within ±10% of forming a 90° angle with the second direction in some embodiments, within ±5% of forming a 90° angle with the second direction, and even within ±2% of forming a 90° angle with the second direction in some embodiments.

[0063]

[0073] For purposes of description herein, the terms "upper," "lower," "right," "left," "vertical," "horizontal," "top," "bottom," and derivatives thereof, shall refer to the structures and methods described as oriented in the drawing views. The terms "on," "atop," "on top," "located on," or "located atop" mean that a first element, such as a first structure, resides on a second element, such as a second structure, where an intervening element, such as a junction structure, may reside between the first and second elements. The term "direct contact" means that a first element, such as a first structure, and a second element, such as a second structure, are connected without any intermediate layer or structure at the junction of the two elements.

[0064]

[0074] Moreover, the phraseology and terminology used herein is for purposes of description and should not be regarded as limiting. The use of "including," "comprising," "having," "including," "including," "including," and variations thereof herein are meant to encompass the items listed thereafter, and equivalents of those items, as well as additional items.

Claims

1. a plurality of plates arranged in a stack including a first plate and a second plate, the first plate comprising: a first conductive path, at least a portion of the first conductive path being a spiral path, the first conductive path comprising a high temperature superconductor (HTS) material; a first conductive joint arranged inside or outside the spiral path of the first conductive pathway, the first conductive joint being electrically coupled to the HTS material of the first conductive pathway; Equipped with the second plate is arranged adjacent to the first plate in the stack; a second conductive path comprising the HTS material; and a second conductive joint disposed proximate to and electrically coupled to the first conductive joint, the second conductive joint being electrically coupled to the HTS material of the second conductive path; A plurality of plates A magnet comprising:

2. 10. The magnet of claim 1, further comprising a layer of conductive metal between the first and second conductive joints that contacts both the first and second conductive joints.

3. 3. The magnet of claim 2, wherein said layer of conductive metal is a layer of indium.

4. The magnet of claim 1 further comprising at least one bolt coupling said first conductive joint to said first plate.

5. 2. The magnet of claim 1, further comprising at least one bolt coupling the first plate to the second plate, the at least one bolt coupling the first plate to the second plate passing through the first conductive joint and the second conductive joint.

6. 6. The magnet of claim 5, further comprising a first fastener disposed in the first plate and a second fastener disposed in the second plate, and wherein the at least one bolt coupling the first plate to the second plate is further coupled to the first fastener and the second fastener.

7. The magnet of claim 6 , wherein the first fastener and the second fastener contact each other.

8. 7. The magnet of claim 6, further comprising an electrical insulating layer between the first fastener and the second fastener, the first fastener and the second fastener contacting oppositely positioned sides of the electrical insulating layer.

9. 10. The magnet of claim 1, wherein the HTS material of the first conductive path does not contact the second conductive joint and the HTS material of the second conductive path does not contact the first conductive joint.

10. The magnet of claim 1 , wherein at least a portion of the second conductive path is a helical path.

11. The magnet of claim 1 , wherein the first conductive path further comprises a first conductive material in contact with the HTS material.

12. The magnet of claim 1 , further comprising at least one cooling passage disposed in said first plate proximate said first conductive joint.

13. The magnet of claim 1 , wherein the first conductive coupling comprises copper.

14. 2. The magnet of claim 1, comprising a plurality of instances of the first plate and a plurality of instances of the second plate arranged in the stack, the plurality of plates in the stack alternating between the instances of the first plate and the instances of the second plate.

15. 10. The magnet of claim 1, wherein the first plate is formed from a first material in which the first conductive path is formed, the first material comprising steel.

16. The magnet of claim 1 , wherein the spiral path of the first conductive path is a racetrack spiral.

17. The magnet of claim 1 , wherein the HTS material comprises a stack of HTS tapes.

18. 18. The magnet of claim 17, wherein each HTS tape in the stack of HTS tapes comprises a rare earth barium copper oxide (REBCO) material encased in a copper cladding material.

19. 10. The magnet of claim 1, wherein the conductive path of the first plate further comprises Pb and / or Sn solder in contact with the HTS material.

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