Segmented superconducting cable

Abstract

To provide a segmented superconducting cable capable of reducing eddy currents and / or current coupling heating in the superconducting cable by disposing a resistive layer in a structural component of the cable.SOLUTION: The cable 100 comprises a plurality of high temperature superconductor (HTS) components 130a, 130b, 130c, a plurality of electrically conductive segments 110a, 110b, 110c extending along a length of the cable, each of the plurality of electrically conductive segments comprising one of the plurality of HTS components, and an electrically insulating material 120 disposed between adjacent electrically conductive segments of the plurality of electrically conductive segments to electrically insulate the plurality of electrically conductive segments from each other.SELECTED DRAWING: Figure 1

Description

[Background technology]

[0001]

[0001] 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 with liquid helium.

[0002]

[0002] 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

[0003]

[0003] According to some embodiments, a cable is provided comprising a plurality of high temperature superconductor (HTS) components, a plurality of electrically conductive segments extending along the cable, each of the plurality of electrically conductive segments comprising one of the plurality of HTS components, and an electrically insulating material disposed between adjacent electrically conductive segments of the plurality of electrically conductive segments, electrically insulating the plurality of electrically conductive segments from one another.

[0004]

[0004] According to some embodiments, a magnet is provided comprising a coil comprising a plurality of windings of a cable, the cable comprising a plurality of high temperature superconductor (HTS) components, a plurality of electrically conductive segments extending along the length of the cable, each of the plurality of electrically conductive segments comprising one of the plurality of HTS components, and an electrically insulating material disposed between adjacent electrically conductive segments of the plurality of electrically conductive segments.

[0005] The foregoing apparatus and method embodiments may be implemented 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 when read 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, each identical or nearly identical component illustrated in various figures is represented by a like numeral. For clarity, every component may not be labeled in every figure. [Brief explanation of the drawings]

[0007] [Figure 1]

[0007] FIG. 1 is a cross-sectional view of a superconducting cable according to some embodiments. [Figure 2A]

[0008] 1 is a cross-sectional view of an exemplary superconducting cable according to some embodiments. [Figure 2B]

[0009] 2B is a diagram of a single electrically conductive segment corresponding to a portion of the exemplary superconducting cable of FIG. 2A, according to some embodiments. [Figure 2C]

[0008] FIG. 1 is a cross-sectional view of an exemplary superconducting cable, according to some embodiments. [Figure 2D]

[0009] FIG. 2D is a diagram of a single electrically conductive segment corresponding to a portion of the exemplary superconducting cable of FIG. 2C, according to some embodiments. [Figure 3A]

[0010] FIG. 1 depicts eddy currents in a superconducting cable having a single conductive structure supporting multiple high temperature superconductor (HTS) tape stacks, according to some embodiments. [Figure 3B]

[0011] FIG. 1 depicts eddy currents in a superconducting cable comprising four electrically conductive segments, each supporting a separate HTS tape stack and comprising insulating material between the segments, according to some embodiments. [Figure 4A]

[0012] FIG. 1 is a diagram of the performance difference between a superconducting cable having a single conductive structure supporting multiple HTS tapes and a superconducting cable with multiple electrically conductive segments and insulating material between the segments, according to some embodiments. [Figure 4B]

[0012] A diagram of the performance difference between a superconducting cable having a single conductive structure supporting multiple HTS tapes and a superconducting cable having multiple electrically conductive segments and insulating material between the segments, according to some embodiments. [Figure 4C]

[0012] A diagram of the performance difference between a superconducting cable having a single conductive structure supporting multiple HTS tapes and a superconducting cable having multiple electrically conductive segments and insulating material between the segments, according to some embodiments. [Figure 5]

[0013] FIG. 1 depicts a partial cutaway isometric view of a portion of a superconducting cable comprising a plurality of twisted electrically conductive segments, according to some embodiments. [Figure 6A]

[0014] 1A-1C are cross-sectional views of superconducting cables depicting various outer insulation configurations according to some embodiments. [Figure 6B] 1 is a cross-sectional view of a superconducting cable depicting various outer insulation configurations according to some embodiments. [Figure 6C] 1 is a cross-sectional view of a superconducting cable depicting various outer insulation configurations according to some embodiments. [Figure 7]

[0015] 1 is a flowchart of a method of fabricating a superconducting cable, according to some embodiments. [Figure 8]

[0016] FIG. 1 is a perspective view of a fusion power plant with portions removed to illustrate various components of the plant, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0008]

[0017] Operating high-field magnets at high currents (e.g., greater than 5 kA) can pose challenges when operating in variable current mode, commonly referred to as alternating current (AC) mode. In particular, induction heating can occur as a result of the changing magnetic field. If the magnet comprises a current-carrying superconductor, such induction heating can cause at least a portion of the superconductor to become non-superconducting ("normal"), causing temperature instability and possible damage to the magnet. Sources of induction heating can include eddy currents induced in a conductor and / or coupling currents generated in two parallel current paths close to each other.

[0009]

[0018] High-field superconducting magnets often include multiple electrically insulated cable turns grouped in a multi-layer or multi-pancake configuration. This allows the magnet to be driven in AC mode by varying the power supply current over time, thereby changing the magnetic field produced by the magnet over time. During transient events, such as charging or discharging the magnet, each cable turn of the magnet is exposed to a variable magnetic field. As noted above, this variation in magnetic field can induce eddy currents (and therefore heating) in the electrically conducting portions of the cable. Such heating can significantly reduce the superconductor temperature margin (i.e., the difference between the temperature at which the magnet is operating and the temperature above which the superconductor may lose its superconducting properties). Therefore, if uncontrolled, such heating can lead to the superconductor losing its superconducting capability, often referred to as a "quench."

[0010]

[0019] Conventional approaches to reducing AC losses in superconducting cables include reducing the size of the current-carrying wires and / or twisting the wires into spiral windings. Smaller wires can reduce hysteresis losses and the size of coupling currents that occur between parallel current paths, while twisting can reduce the length over which two conductive paths are parallel to one another. As an example, the so-called cable-in-conduit conductor (CICC) braided cable approach includes small diameter filaments that are integrally incorporated and twisted with the conductive wires.

[0011]

[0020] However, these techniques are very difficult or impossible to implement with high-temperature superconductors (HTS), which are not typically formed from wire. Rather, HTS cables typically comprise superconductor components with wide aspect ratios, often referred to as "tapes." However, reducing the size of such tapes to smaller units, and even twisting highly aspected tapes, can be challenging. Therefore, conventional techniques for reducing AC losses in superconducting cables may not be effective with HTS cables.

[0012]

[0021] The present inventors have recognized and appreciated concepts, structures, processes, and techniques for reducing eddy currents and / or current-coupled heating in superconducting cables by disposing resistive layers within the structural components of the cable. In particular, the structure supporting the current-carrying components may be sectioned and at least partially insulated between sections. The introduction of such resistive layers has been observed to reduce eddy currents and coupled heating by a significant factor, as discussed further below.

[0013]

[0022] In at least some implementations, current-carrying components such as HTS tapes can be configured in other ways, as in conventional approaches. Illustratively, a cable can include an electrically conductive structure that supports one or more HTS tapes. The electrically conductive structure, sometimes referred to as a "former," can be segmented so that separate segments of the former each support one or more HTS tapes, and the separate segments are separated from one another by electrically insulating material. When multiple HTS tapes are supported by a single segment of the former, the HTS tapes can be arranged in a stack, layered on top of each other along the same axis as the tape's smallest dimension (e.g., tapes that are long, wide, and have a small thickness are layered in the thickness direction).

[0014]

[0023] According to some embodiments, a superconducting cable can include multiple segments comprising at least one HTS. In some cases, the segments are radial segments comprising at least one HTS. In some cases, the radial segments can exhibit radial symmetry. Each segment can comprise a separate and independent current carrier comprising or consisting of an HTS, and electrical insulators can be disposed between the radial segments. As a result, the cable can include multiple current-carrying regions separated by insulators.

[0015]

[0024] According to some embodiments, a superconducting cable may include a central cooling channel. This channel may run through the interior of the cable and be adjacent to multiple segments of the structure supporting the current-carrying components, thereby providing cooling for the multiple segments and for the HTS components supported by the multiple segments. In some cases, the channel may be formed by removing regions of the cable segments to form an interior hollow space. Additionally or alternatively, the channel may be formed by tubular elements that run through the interior of the cable and provide support for the cooling channel. Such tubular elements may comprise the same or different material as the segments of the structure supporting the current-carrying components.

[0016]

[0025] According to some embodiments, a superconducting cable may comprise multiple segments of a structure supporting current-carrying components twisted about a common axis, each segment of the structure illustratively supporting a respective one of the current-carrying components. While moving, a spiral path may be followed.

[0017]

[0026] Below is a more detailed description of various concepts related to techniques for reducing eddy currents and / or current-coupled heating in superconducting cables, as well as embodiments of those techniques. It should be understood that the various aspects described herein can be implemented in any of numerous ways. Examples of specific implementations are provided herein for illustrative purposes only. Additionally, the various aspects described in the following embodiments can be used alone or in any combination and are not limited to the combinations explicitly described herein.

[0018]

[0027] FIG. 1 shows a cross-sectional view of a superconducting cable according to some embodiments. In the example of FIG. 1, cable 100 comprises multiple electrically conductive segments, here three, 110, separated from one another by electrically insulating material 120. Each of electrically conductive segments 110a, 110b, and 110c, generally referred to herein as 110, supports and is in electrical contact with a respective superconductor component 130a, 130b, and 130c, generally referred to herein as 130. As discussed above, electrically insulating material 120 can reduce eddy currents and coupling heating (and in some cases, by a significant factor) compared to cables that utilize a single region of electrically conductive material to support each of the cable's superconductor components. Insulating material 120 completely insulates each of electrically conductive segments 110 from one another.

[0019]

[0028] During operation of cable 100, at least superconductor components 130 are cooled below their superconducting transition so that they can carry electrical current with zero resistance. The electrically conductive segments 110 act as stabilizers during quenching, so that when one of the superconductor components 130 quenches, heat can be conducted through the electrically conductive segment supporting the quenched superconductor component to the other electrically conductive segments, thereby quenching the entire cross-section of the cable. Subsequently, non-superconducting zones within the superconductor components 130 can be created and propagate along the cable.

[0020]

[0029] According to some embodiments, each electrically conductive segment 110 can be disposed in electrical contact with a respective superconductor component 130. Such contact can occur as a result of direct physical contact between the electrically conductive segment and the respective superconductor component and / or as a result of indirect contact via an intermediate electrically conductive material.

[0021]

[0030] 1, electrically conductive segments 110 are arranged in a radially symmetric manner about the central axis of the cable. This configuration may result in easier fabrication of the cable because the electrically conductive segments can be fabricated with the same cross-sectional dimensions and then assembled into cable 100. Without being hindered by these advantages, the techniques described herein are not limited to electrically conductive segments exhibiting such symmetry, as any suitable size and shape of electrically conductive segments may be used in the cable.

[0022]

[0031] According to some embodiments, the electrically conductive segment 110 may comprise or consist of copper. Copper may represent a desirable material due to its high thermal conductivity, thereby providing a stabilizing function in the event of a quench, and due to its electrical conductivity. Other suitable materials that the electrically conductive segment 110 may comprise or consist of include aluminum.

[0023]

[0032] According to some embodiments, the electrically insulating material 120 is positioned to contact different ones of the electrically conductive segments 110 on either side. As shown in FIG. 1 , the electrically insulating material 120 may be positioned between adjacent pairs of electrically conductive segments 110, contacting both segments of the pair (ideally leaving no or substantially no gaps between the electrically insulating material 120 and each electrically conductive segment). In some embodiments, the insulating material 120 may be provided in the form of a tape that may be positioned between pairs of electrically conductive segments 110. In some cases, the tape may be an adhesive tape and may be adhered to adjacent electrically conductive segments 110 by an adhesive such that the tape is adhered to the electrically conductive segments.

[0024]

[0033] According to some embodiments, the superconductor component 130 may comprise one or more high-temperature superconductors (HTS). As used herein, "high-temperature superconductor" or "HTS" refers to a material having a critical temperature above 30° K, the critical temperature being the temperature below which the electrical resistivity of the material is zero. The critical temperature may in some cases depend on other factors, such as the presence of an electromagnetic field. When referring to the critical temperature of a material herein, it should be understood that this may refer to any material for which a critical temperature occurs under given conditions.

[0025]

[0034] In some embodiments, superconductor component 130 may comprise an HTS tape, which is a long, thin strand of HTS material 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 along the length of the cable, i.e., the length extending into and out of the page in the example of FIG. 1 ). In some embodiments, the HTS tape may comprise polycrystalline HTS and / or have a high level of grain orientation. In some embodiments, superconductor component 130 may comprise an HTS tape stack, which is multiple HTS tapes arranged on top of each other along their width and length. The HTS tape stack may thus have a thickness equal to (or approximately equal to) the thickness of an individual tape multiplied by the number of tapes in the stack.

[0026]

[0035] According to some embodiments, the insulating material 120 may comprise polyimide (e.g., Kapton®), epoxy, phenolic, plastic, elastomer, steel (e.g., stainless steel), or a combination thereof. According to some embodiments, the insulating material may have a breakdown voltage or dielectric strength greater than 25 kV / mm, greater than 50 kV / mm, greater than 75 kV / mm, or greater than 1000 kV / mm.

[0027]

[0036] In some embodiments, insulating material 120 may comprise or consist of a high-resistivity material that is still electrically conductive to some extent. In this regard, reference to material 120 being “insulating” refers to material 120 being much less electrically conductive than the material that comprises electrically conductive segment 110. By way of illustration, in some embodiments, electrically conductive segment 110 may comprise a highly conductive material such as copper, while insulating material 120 may comprise steel, which, while not strictly an insulator, is still much more insulating than copper.

[0028]

[0037] In the example of Figure 1, the electrically conductive segment 110 may provide mechanical integrity to the cable in addition to the previously mentioned advantages regarding quench behavior. The electrically conductive segment 110 may be formed into or conform to a desired shape, providing a significant amount of structural strength to the cable. This is in contrast to other superconducting cables, such as the cable-in-conduit conductor (CICC) braided cable discussed above, which features twisted copper rods that may deform under high electromagnetic loads. do.

[0029]

[0038] According to some embodiments, the electrically conductive segments 110 may be twisted along the length of the cable 110. That is, the electrically conductive segments 110 may be twisted about the central longitudinal axis of the cable, and thus the cross-sectional view of FIG. 1 may be accurate at various points along the cable but for the rotational orientation of the view shown, which rotates about the center of the cable as the cross-sectional view is moved along the length of the cable. A helical path is one example of a twisted path that the electrically conductive segments may follow about the central longitudinal axis of the cable. In such a configuration, the electrically conductive segments 110 may be aligned along respective helical paths with the center of each helix at the central longitudinal axis of the cable. Similarly, the superconductor component 130 may be supported by the electrically conductive segments 110 along the length of the cable in the manner shown in FIG. 1 and thus, further aligned along respective helical paths with the center of each helix at the central longitudinal axis of the cable. Placing the superconductor component 130 along a twisted path reduces the length that the two conductive paths are parallel to each other, and thus may reduce this source of inductive heating.

[0030]

[0039] According to some embodiments, cable 100 may include one or more cooling channels, such as tubular cooling channels, that may run along the cable's longitudinal axis. While the example of FIG. 1 does not illustrate any cooling channels, generally, any number of channels may be formed or otherwise provided through the cable to provide cooling for electrically conductive segment 110 and / or for superconductor component 130. Such channels may, illustratively, provide a path for a cryogenic liquid, such as liquid helium or liquid nitrogen, to flow and transport heat away from electrically conductive segment 110 and / or superconductor component 130. In some cases, one or more cooling channels may be disposed in contact with or in close proximity to electrically conductive segment 110. In such cases, cooling of superconductor component 130 may be achieved indirectly through cooling of the electrically conductive segment. In other cases, one or more cooling channels may be disposed in contact with or in close proximity to superconductor component 130. Coolant may be provided through the cooling channels at high pressures, such as above 2 bar.

[0031]

[0040] 1 , according to some embodiments, cable 100 may include a jacket disposed on the outside of electrically conductive segment 110. The jacket may provide additional structural stability beyond and beyond that provided by electrically conductive segment 110, and may comprise or consist of, by way of example, steel, Inconel®, Nitronic® 40, Nitronic® 50, Incoloy®, or combinations thereof.

[0032]

[0041] FIG. 2A shows a cross-sectional view of a superconducting cable according to some embodiments. Cable 210 is an example of cable 100 shown in FIG. 1 that includes electrically conductive segments 212 arranged in a radially symmetric manner around a central cooling channel 218. The electrically conductive segments 212 are configured to hold respective HTS tape stacks 211 within respective channels 221 (FIG. 2B) within each segment. In the example embodiment of FIG. 2A, channels 221 are disposed on the periphery of each segment. FIG. 2B illustrates a single electrically conductive segment 212 separate from cable 210 to depict channels 221. Note that cable 210 can be produced from three instances of the same electrically conductive segment 212 arranged as shown in FIG. 2A. The example cable of FIG. 2A includes a jacket 219 disposed on the outside of the electrically conductive segments. According to an embodiment, the jacket 219 may comprise or consist of steel, Inconel®, Nitronic® 40, Nitronic® 50, Incoloy®, or combinations thereof.

[0033]

[0042] 2A , HTS tape stack 211 is placed in contact with alloy 215, which provides at least a portion of the electrical contact between the HTS tape stack and each respective electrically conductive segment 212. As discussed further below, one technique for creating electrical contact between the HTS tape and the electrically conductive segments is to fill the space between the tape and the segment with a liquid alloy, such as solder. Thus, alloy 215 can comprise or consist of Pb and / or Sn solder. In some embodiments, alloy 215 can 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.

[0034]

[0043] FIG. 2C shows a cross-sectional view of a superconducting cable according to some embodiments. Cable 260 is an example of cable 100 shown in FIG. 1 that includes electrically conductive segments 262 arranged in a radially symmetric manner around the periphery of a central cooling channel 268. Electrically conductive segments 262 are configured to hold respective HTS tape stacks 261 within respective channels disposed within each segment. In the example embodiment of FIG. 2C, channels 271 are disposed around the periphery of each segment. FIG. 2D illustrates a single electrically conductive segment 262 separate from cable 260 to depict channels 271. Note that cable 260 could be produced from five instances of the same electrically conductive segment 262 arranged as shown in FIG. 2C. According to some embodiments, jacket 269 can comprise or consist of steel, Inconel®, Nitronic® 40, Nitronic® 50, Incoloy®, or a combination thereof.

[0035]

[0044] 2C, HTS tape stack 261 is placed in contact with alloy 265, which provides at least a portion of the electrical contact between the HTS tape stack and each respective electrically conductive segment 262. As discussed further below, one technique for creating electrical contact between the HTS tape and the electrically conductive segments is to fill the space between the tape and the segment with a liquid alloy, such as solder. Thus, alloy 265 can comprise or consist of Pb and / or Sn solder. In some embodiments, alloy 265 can comprise a metal having a melting point that is at least 20°C and 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.

[0036]

[0045] 2A-2D, the channels in the electrically conductive segments in each cable that house the HTS tape stacks are depicted as being rectangular in cross section, but it should be understood that the channels are not limited to this shape. For example, the channels in the electrically conductive segments can be grooves into which a superconductor can be inserted such that the channels have a curved inner surface.

[0037]

[0046] 3A depicts eddy currents in a superconducting cable having a single conductive structure supporting multiple HTS tape stacks, according to some embodiments. As can be noted from the illustrative example of FIG. 3A, eddy currents, represented by arrows, can circulate around the cross section of the cable 310 and through the HTS tape stacks 311. As shown in the example of FIG. 3A, the cable includes a single conductive structure 312 that supports all four of the HTS stacks 311.

[0038]

[0047] In contrast, Figure 3B depicts eddy currents in a superconducting cable comprising four electrically conductive segments 322, each supporting a separate HTS tape stack 321 and comprising insulating material between the segments, according to some embodiments. As can be noted from the illustrative example of Figure 3B, the eddy currents, represented by arrows, circulate in cable 320 in much smaller paths within each separate electrically conductive segment 322 when compared to the paths shown in Figure 3A. As a result of the smaller current loops in cable 320, induction heating in the cable is expected to be much lower than in cable 310 when both cables are operated in AC mode.

[0039]

[0048] 4A-4C further illustrate the performance difference between a superconducting cable having a single conductive structure supporting multiple HTS tapes and a superconducting cable comprising multiple electrically conductive segments and insulating material between the segments, according to some embodiments. Figures 4A-4C depict the results of finite element modeling of these types of cables when each is subjected to a current sweep in a transverse external magnetic field, as shown in Figure 4A. Specifically, as shown in Figure 4A, a 7.5-second +50 kA / -50 kA transport current sweep was simulated in a +25 T / -25 T sweep in a transverse external magnetic field.

[0040]

[0049] As shown in Figure 4B, which depicts the qualitative amount of power stored in a cable by eddy currents over time, sweeping produces a much greater amount of power in a conventional cable (light gray) than in a cable with multiple electrically conductive segments (black). Similarly, as shown in Figure 4C, which depicts the qualitative amount of energy stored in a cable by eddy currents over time, sweeping causes a much greater amount of energy to be stored in a conventional cable (light gray) than in a cable with multiple electrically conductive segments (black).

[0041]

[0050] FIG. 5 is an isometric view of a superconducting cable in which a portion of the outer jacket 502 has been removed to reveal multiple electrically conductive segments in a twisted configuration. As discussed above in connection with FIG. 1 , in some embodiments, multiple electrically conductive segments can be twisted around a common axis along the length of the cable (e.g., the cable's common central longitudinal axis). This configuration is shown in FIG. 5 , which depicts a cable 500 comprising a superconductor component 511 and an insulating portion 516; the intervening electrically conductive segments filling the space between the superconductor component and the insulating portion are not shown for clarity. As discussed above, arranging the superconductor component in a twisted configuration can reduce the length over which two conductive paths are parallel to one another, thereby reducing this source of induction heating. Combined with the reduction in the size of the eddy current loops provided by the insulated electrically conductive segments, as discussed above, induction heating can be dramatically reduced.

[0042]

[0051] 6A-6C depict cross-sectional views of superconducting cables with various external insulation configurations, according to some embodiments. For illustrative purposes, a cable similar to that shown in FIG. 2A is depicted in FIGS. 6A-6C with various external insulation configurations. In the example of FIG. 6A, cable assembly 610 comprises a cable surrounded by jacket 611 (e.g., a stainless steel jacket) encased in a first dielectric layer (e.g., a layer of polyimide such as Kapton®, fiberglass cloth) 612, around which is provided a second dielectric layer (e.g., fiberglass) 613.

[0043]

[0052] 6B, cable assembly 620 includes a first dielectric layer (e.g., a polyimide layer, fiberglass cloth) 624 disposed about the cable, around which is disposed jacket 621. A second dielectric layer (e.g., a fiberglass layer) 623 surrounds jacket 621 (e.g., a stainless steel jacket).

[0044]

[0053] In the example of FIG. 6C, the cable assembly 630 includes a dielectric layer (e.g., a polyimide layer, fiberglass cloth) 634 disposed around the cable, and a jacket 631 (e.g., a stainless steel jacket) disposed around the cable and the dielectric 634.

[0045]

[0054] In some embodiments, the cable assembly may be encased in a dielectric (e.g., fiberglass cloth, polyimide), and then vacuum-pressurized with a dielectric such as epoxy resin to fill the remaining space between the cable turns. Illustratively, the cable assembly may be encased in a first dielectric, arranged in a number of turns, and then vacuum-pressurized with epoxy. The epoxy may be cured by thermal means or otherwise.

[0046]

[0055] In some embodiments, the cable assembly may be disposed within a structural matrix. Illustratively, the jacket may include a number of channels within which the windings of the cable assembly (or the windings of multiple cable assemblies) may be disposed. The jacket may thus act as a structural support (e.g., a structural plate) for supporting the multiple windings of one or more cable assemblies. Such a jacket may, in some embodiments, be surrounded by one or more dielectric layers, as described above.

[0047]

[0056] FIG. 7 is a flowchart of a method of fabricating a superconducting cable, according to some embodiments. Method 700 begins at act 702, in which a plurality of electrically conductive segments are fabricated. Such fabrication may be accomplished by any subtractive or additive method, including, but not limited to, extrusion, machining, and / or additive fabrication. Illustratively, a structure having the cross-section shown in FIG. 2B or 2D (or any other cross-section suitable for subsequent insertion of superconductor components and configuration into a cable) may be fabricated (e.g., from a metal such as copper). In act 702, the segments are further insulated with a suitable insulating material, such as polyimide and / or any other dielectric. In some embodiments, the insulating material may be a tape, which may have an adhesive on either or both sides, by which the insulating material may be adhered to the electrically conductive segments.

[0048]

[0057] In act 704, the electrically conductive segments fabricated in act 702 are assembled into a unitary structure. Optionally, cooling channels may be assembled, formed, or otherwise provided with the electrically conductive segments in act 702. For example, for the cable shown in FIG. 2A, a central cooling channel may be disposed in the center with insulation around the central cooling channel, with multiple electrically conductive segments surrounding the central cooling channel.

[0049]

[0058] In act 706, the assembled collection of electrically conductive segments (and optional cooling channels) can be twisted to produce a shape such as that shown in Figure 5. For example, the assembly can be twisted along its length by holding the ends of the assembly in place and rotating the ends relative to one another.

[0050]

[0059] In act 708, the HTS tape stack may be inserted into a channel or other cavity in the assembled electrically conductive segments. In some cases, the HTS tape stack may be fed into an existing channel or cavity in the electrically conductive segments so that sufficient space is provided in such a channel or cavity to allow the HTS tape stack to be safely pushed through the cable assembly. In act 710, the assembly is inserted into a jack (e.g., stainless steel jacket) provided for structural stability, and the resulting cable is wound into the desired shape.

[0051]

[0060] In act 712, any vacant spaces present in the channels or cavities of the cable (excluding the cooling channels) may be filled by impregnating the spaces with a suitable alloy. In some embodiments, a vacuum pressure impregnation (VPI) process may be performed to fill the spaces with Pb and / or Sn solder. Such a process may include one or more of the following steps: cleaning the vacant spaces in the cable using an acidic solution followed by a water rinse; evacuating the spaces in the cable; purging the spaces with an inert gas; depositing flux into the spaces to cover the HTS tape and the electrically conductive segments; draining any excess flux from the cable; heating the cable to a temperature below or above the temperature at which the alloy to be deposited will melt; and flowing molten alloy (e.g., PbSn solder) into the cable. In some embodiments, the HTS tape may be pre-tinned with a metal (e.g., PbSn solder) to promote a good bond between the HTS tape and the alloy.

[0052]

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

[0053]

[0062] Those skilled in the art will appreciate other embodiments of the concepts, structures, processes, results, and techniques disclosed herein. It should be understood that superconducting cables constructed according to the concepts, structures, processes, and techniques described herein may be useful for a wide variety of applications, including applications in which the superconducting cable 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 such cables may 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 generation; superconducting energy storage; magnetohydrodynamic (MHD) electricity generators; and magnets for material separation, such as mining, semiconductor fabrication, and recycling. It should be understood that the above list of applications is not exhaustive and that there are additional applications in which the concepts, structures, processes, and techniques disclosed herein can be put to use without departing from the scope of those concepts, structures, processes, and techniques.

[0054]

[0063] Having thus described various aspects of at least one embodiment of the disclosed concepts, structures, processes, and techniques, it should be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art.

[0055]

[0064] 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, structures, processes, and techniques described herein. Moreover, although advantages of the present invention are indicated, it is to be understood that not every embodiment of the technology described herein will include every described advantage. Some embodiments may be modified to include any of the features described herein as advantageous. In some instances, one or more of the described features may be implemented to achieve further embodiments. Accordingly, the foregoing description and drawings are by way of example only.

[0056]

[0065] Various aspects of the concepts, structures, processes, and techniques described herein may be used alone, in combination, or in various configurations not specifically discussed in the embodiments described above, 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.

[0057]

[0066] Furthermore, the described concepts, structures, steps, and techniques may be implemented as methods for which examples have been provided. The acts performed as part of a method may be ordered in any suitable way. 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 embodiments.

[0058]

[0067] 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 label to distinguish one claim element having a certain name from another element having the same name (but for the use of the ordinal term).

[0059]

[0068] 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.

[0060]

[0069] 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 a 90° angle with the second direction in some embodiments, within ±10% of a 90° angle with the second direction in some embodiments, within ±5% of a 90° angle with the second direction in some embodiments, and even within ±2% of a 90° angle with the second direction in some embodiments.

[0061]

[0070] Moreover, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use herein of "including," "comprising," "having," "including," "including," "including," and variations thereof are meant to encompass the items listed thereafter, and equivalents of those items, as well as additional items.

Claims

1. A cable, a plurality of high temperature superconductor (HTS) components; a plurality of electrically conductive segments extending along the cable, each of the plurality of electrically conductive segments comprising one of the plurality of HTS components; an electrically insulating material disposed between adjacent electrically conductive segments of the plurality of electrically conductive segments, the electrically insulating material electrically insulating the plurality of electrically conductive segments from one another; A cable.

2. The cable of claim 1 , wherein none of the plurality of electrically conductive segments is in direct contact with any other of the electrically conductive segments.

3. The cable of claim 1 , wherein the cable further comprises at least one internal cooling channel.

4. The cable of claim 1 , wherein the HTS component comprises an HTS tape.

5. The cable of claim 4 , wherein the HTS component comprises a stack of HTS tapes.

6. The cable of claim 1 , wherein the plurality of electrically conductive segments exhibit radial symmetry about a central axis of the cable.

7. 7. The cable of claim 6, wherein the plurality of electrically conductive segments are twisted about the central axis of the cable, and the plurality of HTS components follow a helical path about the central axis.

8. The cable of claim 1 , wherein the electrically conductive segments comprise copper.

9. 10. The cable of claim 1, wherein the HTS component comprises a rare earth barium copper oxide superconductor.

10. 10. The cable of claim 1, wherein the plurality of electrically conductive segments each comprise a groove in an outer surface thereof within which an HTS component of the plurality of HTS components is disposed.

11. The cable of claim 10 , further comprising solder disposed within the grooves of the plurality of electrically conductive segments.

12. The cable of claim 1 , wherein the electrically insulating material comprises a polyimide.

13. 10. The cable of claim 1, further comprising a layer of fiberglass surrounding said plurality of HTS components, said plurality of electrically conductive segments, and said electrically insulating material.

14. 1. A magnet comprising a coil comprising a plurality of windings of a cable, said cable comprising: a plurality of high temperature superconductor (HTS) components; a plurality of electrically conductive segments extending along a length of the cable, each of the plurality of electrically conductive segments comprising one of the plurality of HTS components; an electrically insulating material disposed between adjacent electrically conductive segments of the plurality of electrically conductive segments; Equipped with magnet.

15. 15. The magnet of claim 14, wherein none of the plurality of electrically conductive segments is in direct contact with any other of the electrically conductive segments.

16. The magnet of claim 14 , wherein the cable further comprises an inner cooling channel adjacent each of the plurality of electrically conductive segments.

17. The magnet of claim 14 , wherein the HTS component comprises an HTS tape.

18. 18. The magnet of claim 17, wherein the HTS component comprises a stack of HTS tapes.

19. 15. The magnet of claim 14, wherein the plurality of electrically conductive segments exhibit radial symmetry about a central axis of the cable.

20. 20. The magnet of claim 19, wherein the plurality of electrically conductive segments are twisted about the central axis of the cable, and the plurality of HTS components follow a helical path about the central axis.

21. The magnet of claim 14 , wherein the electrically conductive segments comprise copper.

22. The magnet of claim 14 , wherein the HTS component comprises a rare earth barium copper oxide superconductor.

23. 15. The magnet of claim 14, wherein the plurality of electrically conductive segments each comprise a groove in an outer surface thereof within which an HTS component of the plurality of HTS components is disposed.

24. 24. The magnet of claim 23, further comprising solder disposed within the grooves of the plurality of electrically conductive segments.

25. The magnet of claim 14 , wherein the electrically insulating material comprises polyimide.

26. 15. The magnet of claim 14, further comprising a layer of fiberglass surrounding the plurality of HTS components, the plurality of electrically conductive segments, and the electrically insulating material.

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