Low voltage insulation for high temperature superconducting magnets.

Abstract

An insulating layer for use in systems utilizing high-temperature superconductors (HTS) is described. The insulating layer comprises a first layer of insulating material, a second layer of insulating material, and a third layer of conductive material positioned between the first and second layers. Both the electrically insulating material of the first layer and the electrically insulating material of the second layer are resistant to rubbing forces. A third layer is provided made of a material that is resistant to oxidative decomposition reactions, weather, and radiation, and to wear due to rubbing and friction at cryogenic temperatures. In one application, the insulating layer can be positioned at the interface between the toroidal field (TF) coil and the central solenoid (CS) of a high-temperature superconducting magnet.

Description

[Technical Field]

[0001]

[0001] This application relates to high temperature superconducting magnets.

[0002]

[0002] The foregoing features can be more fully understood from the following description of the drawings. The drawings are helpful in explaining and understanding the disclosed technology. Because it is often impractical or impossible to show and describe every possible embodiment, the figures provided show one or more exemplary embodiments. Therefore, the figures are not intended to limit the scope of the invention. Like numbers in the figures represent like elements. [Brief explanation of the drawings]

[0003] [Figure 1A]

[0003] FIG. 1 is an isometric view of a tokamak fusion reactor design. [Figure 1B]

[0004] 1 is a cross-sectional view of a conductive structure (e.g., a stack of high temperature superconducting magnet pancakes). [Figure 2A]

[0005] Cross-sectional view of the toroidal field (TF) coil and central solenoid (CS). [Figure 2B]

[0006] FIG. 2B is a diagram of an enlarged portion of the TF coil and CS of FIG. 2A. [Figure 3]

[0007] FIG. [Figure 4]

[0008] FIG. 1 is a cross-sectional view of two structures with an insulating layer located between the structures. [Figure 5]

[0009] FIG. 1 is a cross-sectional view of two structures with an insulating layer located between the structures. [Figure 6]

[0010] FIG. 1 is a plan view of a CS wrapped around an insulating layer. [Figure 7]

[0011] FIG. 1 is a plan view of a CS wrapped around an insulating layer. [Figure 8]

[0012] FIG. 1 is a plan view of a CS wrapped around an insulating layer. [Figure 9]

[0013] FIG. 1 is a cross-sectional view of two structures, a fastener holding the two structures, and an insulating layer between the structures and the fastener. [Figure 10]

[0014] FIG. 2 is a cross-sectional view of a section of an insulating layer. [Figure 11A]

[0015] FIG. 1 is a cross-sectional view of an insulating stack including alternating plates and alternating insulating layers. [Figure 11B]

[0016] FIG. 10 is a cross-sectional view of another embodiment of an insulating stack including alternating plates. DETAILED DESCRIPTION OF THE INVENTION

[0004]

[0017] The concepts, systems, structures, and techniques described herein solve problems in systems utilizing high temperature superconducting (HTS) materials. In particular, the concepts, systems, structures, and techniques described herein relate to low voltage isolation between structural elements that may be included in an HTS system (i.e., isolating electrically conducting structure 1 from structure 2).

[0005]

[0018] As an example, the described concepts, systems, structures, and techniques may find use in HTS magnets. Such insulation may be located on flat or curved interfaces between electrically conductive structural elements that are continuously or incrementally exposed to different potentials (e.g., potentials of about 10 V or less). For clarity, it should be understood that reference may be made herein to the use of the insulating structures and techniques described herein with HTS magnets in fusion reactors (including, but not limited to, HTS magnets contained in fusion reactors). Specific types of HTS magnets may also be referenced herein. Such references are not intended to, and should not be construed as, limiting. It is recognized that the concepts, systems, structures, and techniques described herein generally relate to insulating one electrically conductive structure from a second structure. In embodiments, the insulated structures may be used, for example: (a) between so-called "pancakes" in an HTS magnet (e.g., between pancakes in a toroidal field (TF) magnet included in a fusion reactor); (b) as ground insulation between the pancakes and the structural case of the HTS magnet (e.g., a TF magnet); (c) as insulation between structural TF elements; (d) as insulation between the structural TF elements and the central solenoid (CS) (e.g., the outer diameter (OD) of the CS); and (e) to insulate any other electrically conducting parts bolted or otherwise joined together (e.g., as shown in FIG. 9).

[0006]

[0019] In some cases, the surfaces of the structural elements of the HTS magnet may be geometrically aligned with one another across a large contact area. The magnetic field (and resulting Lorentz force) generated by the HTS magnet may cause the structural elements on both sides of the contact interface to move, which may damage the structure of the HTS magnet. For example, the Lorentz force may cause the structural elements of the HTS magnet to rub and wear.

[0007]

[0020] 1A is a perspective view of a fusion reactor 10 including a vacuum vessel 11. The vacuum vessel 11 is located within a radiation shield (or "shield tank") 41. The vacuum vessel 11 and radiation shield are located around a central solenoid 12. A toroidal field (TF) magnet 13 is located around the vacuum vessel 11. In this exemplary embodiment, the TF magnet is provided as an HTS magnet 13 having a D-shape. Of course, other magnet shapes may be used.

[0008]

[0021] The body of an HTS magnet may be formed from a conductive metal, often in the form of a base plate with one or more superconducting current paths formed from a stack of HTS tapes provided therein. The combination of the base plate and HTS tapes may be referred to herein as an "HTS coil," "HTS magnet," or simply "coil."

[0009]

[0022] In embodiments, the HTS tape can be wrapped around the body of the base plate one or more times to form a looped winding through the HTS magnet. This allows current to flow through the HTS coil to generate a high-strength magnetic field. The conductive path through the base plate can further include a conductive material (sometimes referred to as a "co-wound") located therein (in addition to the HTS tape). In embodiments, the conductor can be located on the HTS as a cap. According to some embodiments, the HTS can include a rare-earth barium copper oxide superconductor (REBCO), such as yttrium-barium-copper-oxide (YBCO). In some embodiments, the HTS can comprise a stack of co-wound HTS tapes.

[0010]

[0023] In embodiments, HTS magnet 13 may include multiple HTS coils positioned in a stack or wedge (e.g., having a wedge shape as shown in FIGS. 1B and 2A). In this configuration, the HTS coils may be referred to as "pancakes," and the stacked HTS coils may be referred to as a "stack of pancakes" (and, when arranged in a wedge configuration as shown in FIGS. 1B and 2A, may also be referred to as a "wedge of pancakes"). These HTS pancakes may be used, for example, to form the toroidal field magnet 13 shown in FIG. 1B.

[0011]

[0024] Referring to FIG. 1B, a cross-sectional view of a wedge of HTS pancakes is shown. Each pancake 102 may include a base plate 104, typically formed from a conductive material such as steel. The base plate 104 may have a groove 106 (or a series of grooves) through which an HTS material 108 (e.g., HTS tape) is wound. In other embodiments, the channel 106 may correspond to a cooling channel, and HTS may be deposited in other grooves (not shown in FIG. 1B). The HTS material 108 may form a superconducting path that can carry an electric current to form a magnetic field. In an embodiment, the HTS material 108 comprises a stack of HTS tape. In an embodiment, the pancakes may form a toroidal shape (as shown in FIG. 1A) and thus may be referred to as a toroidal field (TF) coil.

[0012]

[0025] 2A and 2B, in which like elements are provided with like reference numerals, multiple TF coils 202 are positioned around a central solenoid (CS) 204, which may be the same as or similar to the central solenoid 12 described above in connection with FIG. 1A. The TF coil 202 comprises multiple TF pancakes 204 configured with wedge shapes that, when joined together, form a coil pack, indicated by reference numeral 205 in FIGS. 2A and 2B. The pancakes 204 include one or more traces 205 in which HTS material is located (e.g., which may be located in the HTS traces 205). Insulation 208 (so-called pancake-to-pancake insulation) is positioned between the TF pancakes 204. Ground insulation 210 is positioned around the TF pancakes 204 to encase the TF pancakes 204 within a TF structural case 212 (which may also be referred to as a "TF coil case" or more simply "coil case").

[0013]

[0026] Insulation material 214 (so-called inter-TF insulation material) is located between each TF coil case 212.

[0014]

[0027] Insulation 216 (so-called TF-CS insulation) is located at the interface between the CS and the TF coil case (ie, between the outer diameter (OD) of the CS 204 and the inner diameter (ID) of the TF coil case 212).

[0015]

[0028] As illustrated, the TF pancake 200 includes inter-pancake insulation 206 located around the TF pancake 200, with ground insulation 210 located between the TF coil and the TF coil case 203. Without the inter-pancake insulation 206, during charging of the TF coil, the transmission current would bypass the HTS windings through the electrically conductive structure, causing charging to take much longer. Furthermore, during plasma shots created by time-varying the magnetic field, eddy currents could cause the HTS magnets to heat up (and, in a worst-case scenario, exceed the superconducting limit or at least impose a significant thermal load on the cryogenic device).

[0016]

[0029] Figure 2B shows the eddy current paths for the uninsulated CS-TF interface and the insulated TF-TF interface.

[0017]

[0030] Referring now to FIG. 2B, there is shown an interface between the OD of the CS and the ID of the TF coil case that may exist in a fusion reactor design. If the TF coil is backed against the OD of the CS (i.e., without an insulating layer between them), eddy currents can occur. The paths of such eddy currents for the uninsulated CS-TF interface and the insulated TF-TF interface are shown by reference numeral 218.

[0018]

[0031] At this interface, the Lorentz force due to the constant TF current and the fluctuating CS current during the plasma shot is always compressive (e.g., up to standard pressure of 300 MPa). The interaction between the time-varying magnetic field of the CS along with the TF coil current generates so-called out-of-plane (OOP) forces, which tend to deform the TF inner leg, i.e., the tangential and circumferential contacts with the CS, relative to the cylindrical interface between the TF and CS OD faces. Furthermore, the axial magnetic flux fluctuations generated by the CS and poloidal field (PF) coil currents and plasma during the shot induce eddy currents in the steel structure of the TF coil case. Even if the TF coil cases are perfectly insulated from each other, without electrical insulation at the TF-CS interface 205, such vortices could form a closed circular path (indicated by arrow 218) through the TF coil case 203, bridged through electrically conducting structures around the CS OD, as shown in Figure 2B. The resistive losses associated with these eddy currents increase the heat load in cryogenic systems and are preferably reduced (and ideally reduced to the smallest possible value). This can be achieved by reducing the thickness of the CS OD TF inter-coil electrical conduction bridge.

[0019]

[0032] Alternatively, and as shown in Figure 2B, eddy currents can be reduced or substantially eliminated (and ideally eliminated entirely) by introducing insulation 216 between the CS OD and the TF coil case ID. Again, this electrical insulation resists the "rubbing" mechanical interaction between the TF inner leg and the CS OD.

[0020]

[0033] 3, there is shown an insulating layer 300 that can be placed in any desired location, including, but not limited to, (a) pancakes in a TF magnet between themselves (e.g., pancake-to-pancake insulating layer 208 in FIG. 2A), (b) ground insulating material between pancakes and the structural case of a TF magnet (e.g., insulating material 210 in FIGS. 2A and 2B), (c) insulating material between structural TF cases (e.g., insulating material 214 in FIGS. 2A and 2B), (d) insulating material between the structural TF case and the OD of a central solenoid (CS) (e.g., insulating material 216 in FIGS. 2A and 2B), and / or (e) insulating layers (or, more simply, "insulators" or "insulators") between some or all of the conductive parts and any other electrically conductive parts bolted or otherwise fastened together (e.g., as shown in FIG. 9). Accordingly, any of insulating layers 206, 208, 210, 214, 216 can be provided with a structure of insulating layer 300. In the exemplary embodiment of FIG. 3 , insulation layer 300 comprises three layers: top layer 302 and bottom layer 304 formed from a wear-resistant insulating material; and middle layer 306 formed from a conductive material, such as sheet metal (e.g., steel). In an embodiment, layer 306 may be provided by a shim stock sheet metal having a thickness of approximately 0.25 mm with wear-resistant insulating materials 302, 304 deposited on opposite sides thereof. In an embodiment, one or all of layers 302, 304, 306 may themselves comprise multiple layers. The plates used to form the layers of shim stock sheet metal 306 may be referred to herein as “sheet metal plates.” However, the plates may be formed from other substances (e.g., any electrically conductive material) and are not limited to sheet metal.

[0021]

[0034] In embodiments, the insulating material may be resistant to oxidative degradation, weathering, and radiation, as well as to abrasive and fictional wear at cryogenic temperatures. For example, the insulating layer may be formed from or comprise an insulating material, such as a polymer, e.g., a polyimide, e.g., JARO CORP's 650- or 650-T series polyimide. In embodiments, the metal layer 306 may have a thickness ranging from about 25 micrometers to about 0.25 mm. The metal layer may be relatively elastic, which may allow the metal layer to withstand scraping or compressive forces from a magnet. The insulating material layers 302, 304 may, in some examples, have a thickness ranging from about 25 micrometers to about 2.0 mm.

[0022]

[0035] In an embodiment, insulating layer 300 may be formed into a plate that may be placed in any desired location, including, but not limited to, insulation between pancakes in a TF magnet (e.g., pancake-to-pancake insulation 208 in FIG. 2A ), ground insulation between pancakes and the structural case of a TF magnet (e.g., ground insulation 210 in FIG. 2A ), TF-to-TF insulation between structural TF cases (e.g., insulation 214 in FIG. 2A ), insulation between the structural TF case and the OD of a CS (e.g., insulation 216 in FIG. 2A ), and / or insulation between any other electrically conductive parts bolted or otherwise fastened together.

[0023]

[0036] Insulating layer 300 may be provided with any surface shape (e.g., any flat or contoured surface shape). In embodiments, it may be desirable to provide an insulating layer (e.g., insulating layer 300) that conforms to the shape of the structure between which it is located. In embodiments, an insulating layer (e.g., insulating layer 300) may be located between some or all of the regions / surfaces of the TF-CS interface depending on design requirements.

[0024]

[0037] In embodiments, an insulating layer (e.g., pancake-to-pancake insulator, such as insulator 208 in FIG. 2A ) may be located on or between some or all areas / surfaces between pancakes included in an HTS magnet. In embodiments, an insulating layer (e.g., ground insulator 210 in FIG. 2A ) may be located on or between some or all areas / surfaces of the interface between the pancake and the structural case of the TF magnet. In embodiments, an insulating layer (e.g., insulator 214 in FIG. 2A ) may be located on or between some or all areas / surfaces of the structural TF case. In embodiments, an insulating layer (e.g., insulator 216 in FIGS. 2A and 2B ) may be located on or between some or all areas / surfaces of one or more structural TF coil cases and the OD of the central solenoid (CS). In embodiments, an insulating layer may be located on or between some or all areas / surfaces of any electrically conductive parts bolted or otherwise fastened together.

[0025]

[0038] As previously described in connection with FIG. 2B , when located at the interface of the TF coil case and the CS, the insulating layer 300 can reduce the flow of eddy currents between the TF and the CS, as described above. Therefore, the damaging Lorentz forces that can result from these eddy currents can also be reduced or eliminated. In embodiments, multiple insulating layers can be stacked together, and these multiple layers can be located at the interface between the TF coil and / or the CS.

[0026]

[0039] The insulating layer is positioned to reduce (and ideally prevent) the formation of the above-mentioned eddy currents, which may reduce (and ideally prevent) damaging Lorentz forces from crushing or rubbing against the coils, but even in the presence of damaging Lorentz forces, the insulating layer may provide physical protection for structures (such as the TF coil, CS, or other structures included in the magnet) from damage.

[0027]

[0040] As mentioned above, the magnetic fields generated by the magnets, particularly during starting, stopping, or quenching of the magnets, can generate squashing or rubbing Lorentz forces between the TF pancakes, and / or between the TF pancakes and the structural case of the TF, and / or between the structural case of the TF and the CS, and / or between the structural TF case and / or any other electrically conductive parts bolted or otherwise fastened together with insulators between some or all of the conductive parts.

[0028]

[0041] In embodiments, if these forces remain significant even when insulating layers are present between the pancakes, and / or between the TF pancake and the structural case of the TF, and / or between the structural case of the TF and the CS, and / or between the structural TF case, and / or any other electrically conductive parts bolted or otherwise fastened together with insulators between some or all of the conductive parts, the insulating layers may act to withstand and / or absorb those forces so that the aforementioned structures (e.g., pancakes, structural case of the TF, CS) are not damaged.

[0029]

[0042] In some instances, the insulating layer may be damaged by Lorentz forces. In these cases, the insulating layer 300 may be replaced.

[0030]

[0043] As shown, in Figures 4 and 5, there are two layers of insulation between the sheets, and gaps may exist between the insulation layers. Of course, it should be understood that in some embodiments, it may be desirable or necessary to utilize other configurations. For example, in some embodiments, the option of using a stack comprising alternating layers of metal sheets and insulators (e.g., one metal sheet, one insulator layer, another metal sheet, another insulator layer, etc.) may be used. Such embodiments may comprise one or more metal sheet layers and one or more insulator layers.

[0031]

[0044] Referring to Figures 4 and 5, multiple insulating layers (e.g., insulating layers 300a, 300b in Figure 4) can be disposed between two structures (e.g., structures 406, 408 in Figure 4), at least one of which is electrically conductive.

[0032]

[0045] For example, in FIG. 4, a pair of insulating layers 300a, 300b are positioned between electrically conductive structures 406 and 408. Similar to insulating layer 300 (FIG. 3), each insulating layer 300a, 300b comprises a first insulating material layer and a second insulating material layer 302a, 304a, 302b, 304b positioned around a respective one of conductive materials 306a, 306b (e.g., sheet metal layers). Thus, when insulating layers 300a, 300b are positioned adjacent to each other, the bottom insulating material 304a of insulating layer 300a and the top insulating material 302b of insulating layer 300b are in contact. According to this approach, two insulating material layers (layers 304a, 302b) are positioned between conductive (e.g., metal) sheets 306a, 306b. Thus, when one layer of insulating material (or a portion of one layer of insulating material) is damaged or otherwise compromised, the other layer of insulating material may still be structurally intact.

[0033]

[0046] In Figure 5, multiple insulating layers, in this example four insulating layers 300a-300d, are positioned between two structures 418 and 420, at least one of which is electrically conductive. The structures 418, 420 in Figures 4 and 5 can be, for example, (a) a pancake in a TF magnet, or (b) a pancake and a structural case of a TF magnet, or (c) a pair of structural TF cases, or (d) a structural TF case and an OD of a central solenoid (CS), or (e) any other electrically conductive parts bonded together or otherwise immobilized or fixed (e.g., bolted) with one or more insulating layers 300a-300d positioned therebetween (e.g., as shown in Figure 9).

[0034]

[0047] The use of more than one insulating layer between structures (e.g., structures 418, 420) can increase the electrical resistance between the structures (e.g., between the TF-CS interfaces) and can further provide additional physical protection from crushing or rubbing forces.

[0035]

[0048] 6 is a plan view of a structure 600 (e.g., a TF coil case) surrounded by an insulating layer 602, which may be the same as or similar to any of the insulating layers described herein. In this example, the insulating layer (e.g., layer 602) may be spirally wound around the structure 600.

[0036]

[0049] 7 and 8, in some instances, it may be beneficial to make the spirally wound insulating layer intermittent to prevent high voltage buildup between the ends of the spiral. To mitigate high voltage buildup, interruptions (e.g., interruptions 702) can be created in the spiral insulating layer 704 so that the spiral forms shorter segments (e.g., segments separated by interruptions or openings 702). The shorter segments reduce the likelihood of high voltage buildup between the ends of any individual segment.

[0037]

[0050] 8, insulating layer 802 is formed from overlapping segments 802a, 802b, 802c (e.g., each segment may correspond to an insulating layer, such as any of the insulating layers described herein). Segments 802a, 802b, 802c may be independently layered around structure 804. Similar to the segmented spiral of insulating layer 704, each segment of layer 802 is relatively short so that high voltages cannot develop between the ends of the segments. In an embodiment, the interruptions may be formed using a water jet cutter or other type of cutting tool.

[0038]

[0051] Figure 9 illustrates the above-described connection of two structural elements 902, 904 (indicated by hatched shading in Figure 9). In this exemplary embodiment, the structural elements 902, 904 are fastened via bolts 906 and nuts 908, with insulation located between at least some surfaces of the structural elements, bolts, and nuts. Fastening structures and techniques other than nuts and bolts may be used to fasten the structural elements, and the insulation described herein may be used with such techniques. The structural elements 902, 904 may correspond to, for example, pancakes of Ni magnets.

[0039]

[0052] The insulating material may form a washer 918 under the head of the nut 908 and bolt 906, and a wrap 912 around the bolt. A thin layer of Teflon (or other insulating material) may be placed at the interface between the laminated washer 918 and the head 916 or nut of the bolt 906 to reduce friction due to tightening. The wrap around the cylindrical portion of the bolt 914 may be arranged in a spiral (e.g., as shown in FIG. 6) to simplify its application and to avoid different sizing for different diameters of bolts.

[0040]

[0053] Although not shown, multiple bolts or fasteners may be used to secure the structure together.

[0041]

[0054] As mentioned above, an insulating layer 910 may be located between structural element 902 and structural element 904. As further mentioned above, eddy currents may be generated during magnet startup, shutdown, or quench events. To reduce or prevent eddy currents from flowing through fasteners (e.g., bolt 908 and / or nut 908), an insulating layer may be located between bolt 906 and pancakes 902, 904 and between nut 908 and structural elements 902, 904. Thus, providing an insulating layer around bolt 906 may reduce or eliminate eddy currents and, as a result, reduce or eliminate harmful Lorentz forces caused by eddy currents.

[0042]

[0055] In this example, the bolt 906 may be wrapped with a layer of insulating material 912 to provide insulation between the bolt 906 and the structural elements 902, 904. The shaft portion 914 of the bolt that passes through the pancake may be smooth and free of threads so that the insulating layer 912 can be more easily wrapped around the shaft 914 and so that the interface between the bolt and the insulating layer 912 is gap-free.

[0043]

[0056] An insulating layer 918 may be added between the bolt head 916 and the pancake to provide insulation between the pancake and the bolt head 916. Similarly, an insulating layer 920 may be added between the nut 908 and the pancake.

[0044]

[0057] 10 , to prevent electrical shorting and / or arcing between sections of the conductive layers, one or more insulating material layers may encase (and / or overlap) the conductive layer segments (e.g., insulating material layers 1003a, 1003b extend beyond the ends of each of conductive layers 1007a, 1007b). As further shown in FIG. 10 , insulating layer segment 1002 and insulating layer segment 1004 share an insulating material layer. For example, insulating material layer 1006 forms the top layer of insulating layer segment 1004 and the middle layer of insulating layer segment 1002 (thus, insulating material 1006 is shared between insulating layer segments 1002, 1004). Similarly, insulating material layer 1008 forms the bottom layer of insulating layer segment 1002 and the middle layer of insulating layer segment 1004. The sharing of an insulating material layer (e.g., layers 1006, 1008) may extend across two or more insulating layer segments.

[0045]

[0058] 11A and 11B, where like elements are provided with like reference numerals, another embodiment of a section of an insulating layer 1100 that can prevent electrical shorting or arcing is shown. One or more insulating material layers 1102 can be positioned around a conductive layer 1106, with at least some of the insulating material layers 1102 enveloping (and / or overlapping or extending beyond) the edges of the conductive layer.

[0046]

[0059] Insulating layer 1100 includes multiple insulating material layers (e.g., insulating material layers 1102) alternating with multiple conductive layers 1106. As indicated by reference numeral 1104, the edges of at least some of insulating material layers 1102 extend beyond (or overlap) the edges of conductive layers (e.g., sheet metal plates) 1106. Overlapping the edges of insulating material 1104 may prevent arcing between stacked conductive layers (e.g., conductive layers 1106 between insulating layers 1102).

[0047]

[0060] Further Modifications of the Insulating Layer

[0048]

[0061] The sheet metal plate of the insulating layer may be coated with insulating, low or high friction, scuff resistant or other material, or may be several overlapping layers thereof.

[0049]

[0062] The sheet metal plates may be covered with the same coating on both sides or with different materials on each side. In particular, the surface of the structure exposed to the rubbing surface may be plated or otherwise provided with a rub-resistant material and insulated against the stack face. Similarly, a low-friction material may be present on the surface facing the structure and on the insulated surface, on the other hand.

[0050]

[0063] Sheet metal plates with different coatings or combinations of coatings can be assembled in a stack, with scuff-resistant or low-friction coatings on the faces and insulation within the stack.

[0051]

[0064] The same insulating effect can be achieved by stacking plates alternately with insulating films, such as Kapton, Mylar, Teflon, etc., or by painting or otherwise applying a hardened insulating substance, such as epoxy resin or Apiezon-N, or a combination thereof. In some applications, adhesion between the insulating material and the plates may not be required due to technical requirements, and the structure can be formed by stacking alternating layers of plates and insulating films without any adhesive substance between them.

[0052]

[0065] Various variations of "partially enveloping" structures between the plates and insulating film to avoid short-circuit impedance paths (or, more simply, "short circuits") from occurring between the edges of the electrically conducting plates.

[0053]

[0066] To prevent local short circuits that may occur due to the sharp edges of the plates cutting through the insulating layer, the edges of the plates may be otherwise modified to be rounded by adding a chamfer with a deburring tool.

[0054]

[0067] Multiple plates containing the same in-plane shape can be cut simultaneously using waterjet cutting techniques.

[0055]

[0068] Tap welding of the stack of insulated plates may be acceptable in certain applications, providing a higher mechanical sustainability of the insulating layers on the mutually facing surfaces of the insulating plates.

[0056]

[0069] The insulating plates may be made of ferromagnetic metal. In the presence of an external magnetic field, the plates are magnetized in the same direction and, due to their proximity, stick to each other across the entire contact surface due to the very strong attractive pressure. This reduces or eliminates the possibility of the plates sliding against each other, thus providing insulation integrity between the insulating plates. Especially in the case of an external magnetic field perpendicular to the surface of the plates, as in the insulating layer between the pancakes described above, the distortion of the magnetic field due to the presence of the ferromagnetic material is negligible due to the small thickness of the plates.

[0057]

[0070] In addition to steel, high electrical resistance structural materials such as Nitronic 40 or 50, Inconel, Hastelloy, etc. can be used as the base material for the insulating plates.

[0058]

[0071] In embodiments, the structural plate may be made from an electrically insulating material, provided that such material is identified as having adequate mechanical strength.

[0059]

[0072] Various embodiments of the concepts, systems, devices, structures, and techniques claimed to be protected have been described above with reference to the associated drawings. Alternative embodiments may be devised without departing from the scope of the described concepts, systems, devices, structures, and techniques. It should be noted that various connections and relationships (e.g., above, below, adjacent, etc.) may be used to describe elements in the description and drawings. These connections and / or relationships may be direct or indirect unless otherwise specified, and the described concepts, systems, devices, structures, and techniques are not intended to be limiting in this respect. Thus, coupling of entities may represent direct or indirect coupling, and relationships between entities may be direct or indirect relationships.

[0060]

[0073] As an example of an indirect positional relationship, placing element "A" above element "B" may include a situation where one or more intermediate elements (e.g., element "C") are between element "A" and element "B," so long as the relevant features and functions of elements "A" and "B" are not substantially altered by the intermediate elements.

[0061]

[0074] Additionally, the following definitions and abbreviations will be used for interpretation of the claims and the specification. The terms "comprises," "includes," "has," "having," or any other variation thereof are intended to cover a non-exclusive inclusion. For example, a device, method, composition, mixture, or article that includes a list of elements is not necessarily limited to only those elements and may include other elements not expressly listed or inherent in such device, method, composition, mixture, or article.

[0062]

[0075] Moreover, the term "exemplary" means "serving as an example, instance, or illustration." Any embodiment or design described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. The terms "one or more" and "at least one" refer to one or more, i.e., any integer number greater than one, i.e., 1, 2, 3, 4, etc. The term "plurality" refers to any integer number greater than one. The term "connected" can include indirect and direct "connections."

[0063]

[0076] References herein to "an embodiment," "one embodiment," "an embodiment," "an example embodiment," "one example," "an instance," "an aspect," and the like indicate that the described embodiment may include a particular feature, structure, or characteristic, but that each embodiment may or may not include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with one embodiment, it may affect such feature, structure, or characteristic in other embodiments, whether or not explicitly described.

[0064]

[0077] Relative or positional terms, including but not limited to "above," "below," "right," "left," "vertical," "horizontal," "top," "bottom," and derivatives thereof, refer to structures and methods described as being oriented in the drawings. The terms "overlying," "on," "on top of," "located on," or "disposed on" mean that a first element, e.g., a first structure, is above a second element, e.g., a second structure, in situations where intervening elements, e.g., interface structures, may be present between the first and second elements. The term "direct contact" means that a first element, e.g., a first structure, and a second element, e.g., a second structure, are connected without any intermediate elements.

[0065]

[0078] The use of ordinal terms, e.g., "first," "second," "third," etc., in the claims to modify claim elements does not in itself imply any priority, precedence, or order of a claim element relative to another element, or the chronological order in which method steps are performed, but is merely used as a label to distinguish a claim element having a particular name from another element having the same name (except for the use of ordinal terms) to distinguish the claim elements.

[0066]

[0079] The terms "approximately" and "about" may 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" may include the target value. The term "substantially equal" may be used to describe values ​​that are in some embodiments 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.

[0067]

[0080] The term "substantially" may be used in some embodiments to describe values ​​within ±20%, in some embodiments within ±10%, in some embodiments within ±5%, and even in some embodiments within ±2% of a comparative measurement. For example, a first direction that is "substantially" orthogonal to a second direction may describe a first direction that, in some embodiments, forms a 90° angle with the second direction within ±20%, in some embodiments, forms a 90° angle with the second direction within ±10%, in some embodiments, forms a 90° angle with the second direction within ±5%, and even in some embodiments, forms a 90° angle with the second direction within ±2%.

[0068]

[0081] The disclosed subject matter is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The disclosed subject matter is capable of other embodiments and of being practiced and carried out in various ways.

[0069]

[0082] Moreover, the phraseology and terminology used in this patent is for the purpose of description and should not be regarded as limiting. Thus, the conception on which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out some of the purposes of the disclosed subject matter. The claims should therefore be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the disclosed subject matter.

[0070]

[0083] While the disclosed subject matter has been described and illustrated in the foregoing exemplary embodiments, the disclosure is made by way of example only. As such, many changes in the details of the implementation of the disclosed subject matter may be applied without departing from the spirit and scope of the disclosed subject matter.

[0071]

[0084] Accordingly, the scope of this patent should not be limited to the described embodiments, but rather should be limited only by the spirit and scope of the claims that follow. All publications and references cited in this patent are expressly incorporated by reference in their entirety.

Claims

1. 1. An insulating layer for use in a system utilizing high temperature superconducting (HTS) material, said insulating layer comprising: a first layer of insulating material; a second layer of insulating material; a third layer of conductive material, said third layer being located between said first layer and said second layer; and The insulating layer comprises:

2. (a) a pancake-to-pancake insulator configured to be located between pancakes in a TF magnet; (b) a ground insulator configured to be located between the pancake and the structural case of the TF magnet; (c) an insulator configured to be positioned between the structural TF cases; (d) an insulator configured to be located between one or more structural TF cases and an outer diameter (OD) of the central solenoid (CS); and (e) an insulating material configured to be positioned between the electrically conductive parts; The insulating layer of claim 1 , wherein the insulating layer is provided as at least one of:

3. The insulating layer of claim 1 , wherein the third layer comprises a ferromagnetic metal.

4. The insulating layer of claim 1 , wherein the insulating material in at least one of the first layer and the second layer is resistant to damage from rubbing forces.

5. The insulating layer of claim 1 located at the interface between the toroidal field (TF) coil and the central solenoid (CS).

6. The insulating layer of claim 1 , wherein the third layer comprises sheet metal.

7. The insulating layer of claim 6 , wherein at least one of the first layer and the second layer comprises a wear-resistant insulating material.

8. The insulating layer of claim 1 , wherein one or more of the first layer, the second layer, and the third layer comprise multiple layers.

9. 10. The insulating layer of claim 1, wherein the third layer is provided to be resistant to oxidative degradation, weather, and radiation, and to wear due to rubbing and friction at cryogenic temperatures.

10. 10. The insulating layer of claim 9, wherein at least one of the first layer and the second layer comprises a 650- or 650-T series polyimide.

11. 10. The insulating layer of claim 1, wherein the third layer comprises sheet metal having a thickness within a range of about 25 micrometers to about 0.25 mm.

12. The insulating layer of claim 1 , wherein at least one of the first layer and the second layer is provided with a thickness within a range of about 0.1 mm to about 2.0 mm.

13. The insulating layer of claim 1 located between pancakes in a toroidal field (TF) magnet.

14. The insulating layer of claim 1 located between the pancake and the structural case of the TF magnet.

15. The insulating layer of claim 1 located between structural TF cases.

16. 1. A high temperature superconducting (HTS) magnet, comprising: a first magnet structure comprising an HTS coil and a housing, the housing being formed from a conductive metal; a second magnet structure comprising an HTS coil and a housing, the housing being formed from a conductive metal; an insulating structure located between the first magnet structure and the second magnet structure; Equipped with The insulating structure is a conductive metal sheet having a first surface and a second surface; a first insulating material located on the first surface of the conductive metal sheet; a second insulating material located on the second surface of the conductive metal sheet; Equipped with 1. An HTS magnet, wherein the insulating structures are positioned such that the first insulating material is adjacent to the first magnet structure and the second insulating material is adjacent to the second magnet structure.

17. 17. The HTS magnet of claim 16, wherein the conductive metal sheet comprises steel.

18. 17. The HTS magnet of claim 16, wherein the first insulating material and the second insulating material comprise polyimide.

19. The insulating structure comprises a plurality of layer structures, each of the plurality of layer structures comprising: a conductive layer having opposing first and second surfaces; one or more layers of insulating material overlying a first one of the first and second surfaces of the conductive layer; one or more layers of insulating material overlying a second of the first and second surfaces of the conductive layer; 17. The HTS magnet of claim 16, comprising:

20. 20. The HTS magnet of claim 19, wherein the conductive layer comprises one or more layers of conductive material.

21. 1. A high temperature superconducting (HTS) magnet, comprising: a first magnet structure comprising an HTS coil and a housing, the housing being formed from a conductive metal; a second magnet structure comprising an HTS coil and a housing, the housing being formed from a conductive metal; at least one bolt assembly comprising a bolt head, a nut, and a shaft extending through the first and second magnet structures; a first insulating layer located between at least a portion of the bolt head and a first magnetic structure; a second insulating layer located between at least a portion of the nut and a second magnetic structure; a third insulating layer positioned around the shaft; Equipped with The first insulating structure, the second insulating structure, and the third insulating structure are a conductive metal sheet having opposing first and second surfaces; a first insulating material located on a first of the first and second surfaces of the conductive metal sheet; a second insulating material located on a second of the first and second surfaces of the conductive metal sheet; and An HTS magnet comprising:

22. an interface layer that provides a buffer for adjacent magnet structures, said interface layer comprising: a first layer comprising an electrically insulating material; a second layer comprising an electrically insulating material; a third layer between the first layer and the second layer, the third layer comprising a metal; and An interface layer comprising:

23. 23. The interface layer of claim 22, wherein both the electrically insulating material of the first layer and the electrically insulating material of the second layer are resistant to scrubbing forces.

24. 24. The interface layer of claim 22 or 23, wherein the first layer and / or the second layer comprises polyimide.

25. 25. An interface layer according to any one of claims 22 to 24, wherein the first layer has a thickness of between 25 micrometers and 50 micrometers.

26. 26. The interface layer of any one of claims 22 to 25, wherein the third layer comprises sheet metal.

27. 27. The interface layer of claim 26, wherein the sheet metal has a thickness between 25 micrometers and 250 micrometers.

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