Techniques for distributing forces in high field magnets and related systems and methods

Abstract

To provide a high temperature superconductor magnet for lowering strain applied to superconducting material in the superconducting magnet by intercepting strain for a mechanically stronger structure, such as a housing of the magnet, and a method for winding a conductive tape for forming the magnet.SOLUTION: A high temperature superconductor magnet 250 comprises: a coil including a high temperature superconductor (HTS) tape 265; and a housing 260 comprising a first partition 271. The coil is arranged within the housing, the partition of the housing is arranged to separate a first portion of the coil from a second portion of the coil such that turns of the first portion of the coil are entirely arranged within the first partition and turns of the second portion of the coil are entirely arranged outside of the first partition, and the first partition comprises a slit through which the coil passes.SELECTED DRAWING: Figure 2A

Description

Technical Field

[0001]

[0001] This disclosure generally relates to superconducting magnet coils, and more particularly to the fabrication and cooling of high-temperature superconductor (HTS) magnet assemblies.

Background Art

[0002]

[0002] A superconductor is a material that has no electrical resistance to an electric current (is "superconducting") below some critical temperature. For many superconductors, the critical temperature is below 30 K such that the operation of those materials in the superconducting state requires significant cooling by liquid or gaseous helium or other cryogens.

[0003]

[0003] Because of the ability of superconductors to carry large electric currents without resistance, high-field magnets are often made of superconductors. Such magnets can carry currents, for example, in excess of 5 kA.

Summary of the Invention

Means for Solving the Problems

[0004]

[0004] According to some aspects, an HTS magnet is provided that includes a coil including an HTS material and a housing having at least a first partition, the coil being disposed within the housing such that windings of a first portion of the coil are entirely disposed within the first partition and windings of a second portion of the coil are entirely disposed outside the first partition, the first partition of the housing being disposed to separate the first portion of the coil from the second portion of the coil, and the first partition comprising a slit through which the coil passes.

[0005]

[0005] According to some aspects, there are a plurality of pancakes, each of the pancakes having one or more windings of a high-temperature superconductor (HTS) tape that generates a magnetic field when an electric current is applied, and each of the pancakes further having one or more joints for electrically coupling one or more windings of the HTS tape as part of an electrical circuit, a plurality of pancakes, and a plurality of cooling plates, each of the cooling plates having a terminal for thermally coupling the cooling plate to a cooling device, a magnet assembly is provided, the plurality of pancakes and the plurality of cooling plates are stacked alternately, and each of the pancakes is electrically coupled by its one or more joints to the joints of one or two adjacent pancakes, thereby forming an operating current path including the HTS tape in each of the pancakes, and each of the pancakes is adjacent to one or two of the cooling plates for removing heat from the pancake by heat conduction to the cooling device.

[0006]

[0006] According to some aspects, a magnet assembly is provided that includes a plurality of pancakes, each of the pancakes including a housing, a plurality of windings of a high-temperature superconductor (HTS) tape disposed within the housing, one or more conductive joints coupled to the HTS tape and disposed outside the housing, and a plurality of coolings, each of the cooling plates having a terminal for thermally coupling the cooling plate to a cooling device, the plurality of pancakes and the plurality of cooling plates are alternately arranged in a stack, and each of the pancakes in the stack is electrically coupled by its one or more conductive joints to the joints of one or two adjacent pancakes in the stack, thereby forming an operating current path through the stack including the HTS tape in each of the pancakes, and each of the pancakes is thermally coupled to one or two of the cooling plates.

[0007] According to some aspects, a housing is provided for holding a tape wound to generate a magnetic field, the housing including a first structural plate having one or more first circular slots, one or more partition walls, each partition wall having a through connection for winding the tape from the inner diameter to the outer diameter of the partition wall, each partition wall being insertable and rotatably inserted into a corresponding slot of the one or more first circular slots, and a second structural plate having one or more second slots, each partition wall being insertably inserted into a corresponding slot of the second slots.

[0008] According to some aspects, a method is provided for winding a conductive tape to form a magnet, the method including: (a) providing a first structural plate having a surface with one or more circular slots and having a first electrical junction at its inner diameter; (b) physically and electrically coupling the conductive tape to the first electrical junction; (c) circularly winding the conductive tape on the surface of the first structural plate until the conductive tape reaches one of the circular slots; (d) insertably inserting a partition wall having a through connection into one of the circular slots, the partition wall being rotated within one of the circular slots such that its through connection aligns with the azimuthal position of the wound conductive tape; and (e) minimizing the gap between the conductive tape and the partition wall by winding the conductive tape around the outer diameter of the partition wall through the through connection on the surface of the first structural plate.

[0009] Embodiments of the above-described apparatus and method may be implemented by any suitable combination of the aspects, features, and operations described above and below. The above and other aspects, embodiments, and features of the present teachings may be more fully understood from the following description in conjunction with the accompanying drawings.

[0010]

[0010] Various aspects and embodiments are described with reference to the following drawings. It should be understood that the drawings are not necessarily drawn to the same scale. In the drawings, each identical or nearly identical component shown in the various figures is represented by a like number. For the sake of clarity, not all components may be shown in each figure.

Brief Description of the Drawings

[0011]

Figure 1

[0011] A cross-sectional view of a superconducting magnet with a structural partition according to some embodiments.

Figure 2A

[0012] A cross-sectional view of a superconducting magnet with a structural partition disposed in a groove according to some embodiments.

Figure 2B

[0013] A cross-sectional perspective view of an exemplary housing according to some embodiments.

Figure 2C

Figure 2D

[0014] A photograph of a magnet with a partition and HTS tape according to some embodiments.

Figure 3A

[0015] A diagram showing various configurations of a through-connection slit of a structural partition according to some embodiments.

Figure 3B

Figure 3C

Figure 4A

[0016] A cross-sectional view of a magnet assembly according to some embodiments.

Figure 4B

[0017] A diagram showing an enlarged portion of the cross-sectional view of FIG. 4A according to some embodiments.

Figure 5

[0018] A photograph of a through-connection slit with a shim, in addition to an HTS tape, according to some embodiments.

Figure 6

[0019] A flowchart of a method for assembling a magnet according to some embodiments.

Figure 7

[0020] An exploded view of the structural and electrical components in a completed pancake according to some embodiments.

Figure 8

[0021] A perspective view of a second type of pancake for stacking in a magnet assembly.

Figure 9

[0022] A view showing a part of a first cooling plate in a magnet assembly between two pancakes electrically joined along their inner diameters.

Figure 10

[0023] A view showing a part of a second cooling plate in a magnet assembly between two pancakes electrically joined along their outer diameters.

Figure 11A

[0024] A sectional view of a magnet assembly coupled to a cooling device.

Figure 11B

[0025] A view showing a part of a cooling device emphasizing a thermal protection radiation shield and a multilayer heat insulator surrounding the magnet assembly.

Figure 12

[0026] A cross-sectional view of a layer of an exemplary coated conductor HTS tape according to some embodiments.

Figure 13

[0027] A three-dimensional graphic of a power plant with a broken part showing various components of a fusion power plant according to some embodiments.

DETAILED DESCRIPTION OF THE INVENTION

[0012]

[0028] As described above, due to the function of superconductors that carry large currents without resistance, high-field magnets are often made of superconducting materials. When the superconducting material is cooled to a temperature low enough (below the temperature at which the electrical resistivity of the material drops to zero) below its critical temperature, the magnet allows current to pass through the superconducting path without loss.

[0013]

[0029] High-temperature superconductors (HTS) provide particularly desirable degrees of freedom for fabricating high-field superconducting magnets. Important features of HTS and HTS rare-earth barium copper oxide (REBCO) superconductors compared to low-temperature superconductors (LTS) include the following. First, HTS exhibits a smaller critical current density with respect to the operating temperature, allowing for a larger operating temperature margin. Second, HTS has a higher operating temperature than LTS, and at the HTS operating temperature, the heat capacity of the material within the superconducting magnet can be significantly higher than at the LTS operating temperature. As a result, HTS magnets can have a smaller sensitivity to local heating. Third, HTS, as will be described in detail later, is electrically non-insulating design principle due to good current sharing between the bundled portions of HTS and has an affinity with it. Fourth, in a non-insulating superconducting magnet, small voltages (e.g., less than about 1 V) may occur in the magnet, but unlike LTS magnets, in HTS superconducting magnets, these voltages may not require high-voltage electrical insulation. And finally, HTS magnets can operate at even higher magnetic fields and can exhibit lower sensitivity to the strength of the magnetic field than LTS magnets.

[0014]

[0030] Regardless of whether the superconducting magnet includes LTS material or HTS material, generally, the superconducting magnet can have a relatively high current density (e.g., a large amount of current per unit volume or per unit cross-sectional area of the superconducting material) while also generating a high magnetic field. However, the large current density and high magnetic field result in significant Lorentz loads (Lorentz forces generated as a result of the current flowing through the magnetic field) being applied to various regions of the superconductor. Such an increase in Lorentz load can lead to a reduction in the structural integrity of the magnet. For example, in a high magnetic field magnet, the strain applied to the superconducting material by the Lorentz load may be sufficient to damage the material and may reduce or prevent its function of carrying current.

[0015]

[0031] The inventors recognize and understand a technique for reducing the strain applied to the superconducting material in a superconducting magnet by arranging structural partitions between windings of the superconducting material that block the strain and transmit it to a mechanically stronger structure such as the housing of the magnet. The structural partitions may be formed with through-connection slits, whereby the superconducting material can easily penetrate the partitions. A number of structural partitions may be inserted between groups of windings of the superconducting material in the magnet, whereby the force can be sufficiently dispersed by the partitions throughout the magnet. At the same time, the number of structural partitions can be selected to minimize the amount of space within the magnet that is occupied by the partitions or that can be otherwise occupied by the conductive superconducting material.

[0016]

[0032] According to some embodiments, the structural partitions may be removable from the housing of the magnet or other support structure. The removable partitions allow the windings of the magnet to be wound in the absence of the partitions, and then, when the magnet is wound sufficiently to the extent that the magnet penetrates the through-connection slits of the partitions, the partitions can be added to the magnet. This process allows the magnet to be wound on a single surface, thereby simplifying the assembly process and allowing the winding to be performed around a structure (partition or central structure of the housing) on the same surface. As the size of the winding increases, the partitions can be added as needed.

[0017]

[0033] According to some embodiments, the structural partition may be movable within the housing of the magnet or other support structure such that the position of the through-connection slit is adjustable within the winding. In some cases, the structural partition may be disposed within a groove, slot, and / or other retaining mechanism within the magnet, whereby the structural partition can be rotated or its position is limited to some extent by the retaining mechanism but can be adjusted in other ways. For example, the structural partition may be circular and may be rotatable within a circular groove. In some cases, the structural partition may be non-circular (e.g., rectangular) and may not be rotatable within the magnet. However, in such cases, small retaining mechanisms may be included in the housing of the magnet or other support structure to reduce the movement of the partition during installation of the winding and the partition. Alternatively, the structural partition may be freely movable within the magnet structure but can be held in an appropriate position to some extent during winding by arranging the partition around the winding of the magnet that substantially fills the interior of the partition. In some cases, the structural partition may include a plurality of joined parts that can move independently while being restricted by connection to other parts. For example, the structural partition may include a plurality of parts arranged in a loop with adjacent parts rotatably joined to each other (e.g., corresponding to a bicycle chain).

[0018]

[0034] According to some embodiments, the superconducting magnet may include an HTS material wound as described above and passing through one or more structural partitions. In some cases, the HTS material may include an HTS tape, which is a long, flat element that includes a layer of polycrystalline HTS in addition to other layers. As used herein, an HTS "tape" may refer to any structure that includes a layer of HTS, such as rare earth copper oxide HTS (e.g., REBCO), such as tape 1200 shown in FIG. 12, and may also include one or more other layers, such as one or more buffer layers, stabilization layers, substrates, overlay layers, and / or clad layers.

[0019]

[0035] In some embodiments, a superconducting magnet comprising one or more structural septa as described herein may include HTS material wound without an insulating material between at least some adjacent turns of the HTS material. In such magnets, herein referred to as non-insulated (NI) magnets (or magnets without insulation), adjacent superconducting windings of the magnet are not insulated from each other, but instead are separated by a conventional conductor (i.e., not a superconductor). When the magnet is operating below the critical temperature of the superconductor, the current flows through the superconductor and does not cross the winding because the superconductor has zero resistance compared to the finite resistance of the conductor present between the windings. flows through the superconductor and does not cross the winding.

[0020]

[0036] In some embodiments, the superconducting magnet may comprise an HTS tape wound around a winding axis such that the x-axis of the tape, as shown in FIG. 12, is aligned parallel to the winding axis. Thus, in the case of a non-insulated magnet design, for example, each HTS tape may contact the face of an adjacent tape (the xy plane of FIG. 12). In some embodiments, the superconducting magnet may include windings of a stack of HTS tapes together with a non-superconducting material such as steel. For example, a stack of 10 - 20 HTS tapes stacked facing the top of a single steel tape having the same width as the HTS tape (the x-direction dimension of FIG. 12) may be wound together around a central structure to form the magnet, and the stack may penetrate one or more structural septa along the winding.

[0021]

[0037] In some embodiments, the superconducting magnet may comprise an HTS tape (or stack of HTS tapes) arranged in a racetrack-shaped helix, and the helix may penetrate one or more structural septa along the winding.

[0022]

[0038] In some embodiments, the housing of the superconducting magnet can include a conductive joint structure configured to couple the superconducting material within the housing to the outer surface of the housing. In the winding, the superconducting material can be electrically coupled (e.g., soldered) to such a joint structure. In some cases, the housing can include multiple joints, such as joints inside and outside the winding of the superconducting material.

[0023]

[0039] In some embodiments, the superconducting magnet can include a plurality of individual windings of superconducting material coupled together. In some cases, the housing of each winding can be stacked or otherwise assembled with a conductive joint on each housing to achieve an electrical connection between the windings. As a result, a conductive path can be formed through the windings, for example, from the inside to the outside of the winding in the first housing, through the joint to the outside of the winding in the second housing, and from the outside to the inside of the winding in the second housing. For at least some use cases, the housing in such an assembly may be referred to herein as a "pancake" with reference to their overall circular and flat shape.

[0024]

[0040] In some embodiments, a stack of windings individually housed as described above can be coupled to one or more cooling plates. The cooling plates can enable conduction cooling and can include a thermally conductive material such as copper. In some embodiments, the cooling plates may be inserted between adjacent housings, and the cooling plates are electrically insulated from the joints between adjacent housings.

[0025]

[0041] The following is a detailed description of various concepts or embodiments thereof related to techniques for reducing strain applied to a superconducting material in a superconducting magnet. It should be understood that the various aspects described herein can be implemented in any of many ways. Specific examples of implementations are provided herein for illustrative purposes only. Further, the various aspects described in the following embodiments may be used alone or in any combination and are not limited to the combinations explicitly described herein.

[0026]

[0042] Figure 1 is a cross-sectional view of a superconducting magnet with a structural partition according to some embodiments. Magnet 100 includes a housing 110 having an upper plate 111, a lower plate 112, and a central structure 113 that may include an inner diameter electrical junction. A single continuous piece of HTS tape 115 is wound around the central structure 113. Alternatively, several joined sections of HTS tape may be wound together as a single winding. For the cross-sectional view shown in Figure 1, the same HTS tape is shown as continuous windings at different radial positions from the central structure. Magnet 100 further includes structural partitions (hereinafter "partitions") 121 and 122 through which HTS tape 115 passes when wound around the central structure. The positions where HTS tape 115 passes through the partitions are not shown in Figure 1 for clarity, but partitions 121 and 122 may include through-connection slits through which HTS tape 115 passes as described above.

[0027]

[0043] In some embodiments, the partition walls 121 and 122 may be movable within the housing 110, such that the through-connection slits in the partition walls can be aligned with the HTS tape in terms of the HTS tape filling the interior of the partition walls. Exemplary through-connection slits are shown in FIGS. 3A - 3C and will be described in detail below. Since there may be cases where the azimuthal position where the tape needs to penetrate the partition wall is unknown, movable partition walls during winding may be beneficial, such that the through-connection slits of the partition walls are arranged at the azimuthal position required when the tape fills all the space inside the partition walls. In some cases, the partition walls may still be correctly moved to the desired azimuthal position, but the partition walls may be limitedly movable because they are arranged in the slots or their movement is restricted in some other way.

[0028]

[0044] In some embodiments, the partition walls 121 and 122 may be circular, and thus the cross-sectional view of FIG. 1 is applicable to any selected cross-section passing through the center of the magnet 100 (excluding the cross-section including the slit passing through the partition wall that looks different from FIG. 1 including the slit). In some embodiments, the partition walls 121 and 122 may be other than circular and instead may have a shape such as a rectangle, or a rectangle with rounded corners (e.g., a racetrack shape), an ellipse, or any other suitable shape.

[0029]

[0045] In some embodiments, the upper plate 111 and the lower plate 112 can include or be made of a high mechanical strength material such as, but not limited to, steel, Inconel®, Nitronic® 40, Nitronic® 50, Incoloy®, or a combination thereof. In some embodiments, the partition walls 121 and 122 can include or be made of a high mechanical strength material such as, but not limited to, steel, Inconel®, Nitronic® 40, Nitronic® 50, Incoloy®, high entropy alloy, high strength composite material, ceramics, or a combination thereof.

[0030]

[0046] According to some embodiments, the HTS tape 115 may include a rare earth barium copper oxide superconductor (REBCO), such as yttrium-based barium copper oxide (YBCO). In some embodiments, the HTS tape may comprise a long and thin strand made of HTS material having cross-sectional dimensions of a thickness (or height) in the range of about 0.001 mm to about 0.1 mm and a width in the range of about 1 mm to about 12 mm. According to some embodiments, each strand of the HTS tape may include an HTS material, such as REBCO, in addition to a conductive material. In some embodiments, the conductive material may be disposed on the REBCO. In some embodiments, the conductive material may be a cladding material, such as copper. In some embodiments, the HTS tape may include polycrystalline HTS and / or may have a high grain alignment.

[0031]

[0047] In some embodiments, the HTS tape 115 may be co-wound with a non-superconductive material, such as steel or copper. The stack of HTS tapes may be co-wound with one or more layers of co-winding material. In some embodiments, additional conductive material may be included in the magnet 100 to fill potential gaps between components. For example, a soft metal, such as indium, may be disposed between either the upper plate 111 or the lower plate 112 and the HTS tape.

[0032]

[0048] Although the central structure 113 is shown in FIG. 1 as being integral as a whole, it will be understood that the structure as shown in the figure is not an essential component of the magnet 100, and generally, the magnet may include any central structure in the housing. For example, the central structure 113 may alternatively be a cylindrical shape with an empty inside wall around which the HTS tape can be wound.

[0033]

[0049] Figure 2A is a cross-sectional view of a superconducting magnet with a structural partition disposed in a groove, according to some embodiments. Magnet 250 includes a housing 260 having an upper plate 261, a lower plate 262, and a central structure 263 that may include an inner diameter electrical junction 278. A single continuous piece of HTS tape 265 is wound from the inner diameter electrical junction 278. Alternatively, several joined sections of HTS tape may be wound together as a single winding. For the cross-sectional view shown in Figure 2A, the same HTS tape is shown as continuous windings at different radial positions from the central structure. Magnet 250 further includes partitions 271 and 272 through which HTS tape 265 passes when wound around the central structure. The positions where HTS tape 265 passes through the partitions are not shown in Figure 2A for clarity, but partitions 271 and 272 may include through-connection slits through which HTS tape 265 passes as described above.

[0034]

[0050] In the example of Figure 2A, partitions 271 and 272 are disposed in grooves formed in upper plate 261 and lower plate 262. This groove can serve as a holding mechanism to hold the partition in place during assembly and / or provide additional structural strength to the magnet such that forces applied to the partition can be easily transmitted by plates 261 and 262. In some embodiments, this groove formed in the surfaces of upper plate 261 and lower plate 262 may have a circular shape. In other cases, the groove formed in the surface of the plate may have different shapes, such as rectangular or rounded rectangular.

[0035]

[0051] In the example of Figure 2A, magnet 260 includes conductive junction structures (hereinafter "junctions") 278 and 279 that are configured to couple the HTS tape inside the magnet to the outer surface as described above. During winding, HTS tape 265 can be electrically coupled (e.g., soldered) to inner junction 278 and outer junction 279. In the example of Figure 2A, inner junction 278 couples the conductive path of HTS tape 265 to the upper surface of magnet 250, while outer junction 279 couples the conductive path of HTS tape 265 to the lower surface of the magnet.

[0036]

[0052] In some embodiments, the inner joint 278 may not extend to the top of the housing in each cross-section, as shown in FIG. 2A. In some cases, the inner joint 278 may only extend to a part of the top of the housing, such as around one side of the housing. Similarly, in some embodiments, the outer joint 279 may not extend to the bottom of the housing in each cross-section, as shown in FIG. 2A. In some cases, the outer joint 279 may only extend to a part of the bottom of the housing, such as around one side of the housing. These configurations may have the advantage that additional elements can be inserted next into the housing while still allowing the conductive path to exit the magnet through the joint.

[0037]

[0053] The central structure 263 is shown in FIG. 2A, but it will be understood that the structure as shown in the figure is not an essential component of the magnet 250, and generally, a magnet may include any central structure in the housing. For example, the central structure 263 may instead consist only of the inner diameter electrical joint 278 and be cylindrical with an empty inside wall around which an HTS tape can be wound.

[0038]

[0054] FIGS. 2B and 2C are cross-sectional perspective views of an exemplary housing (or "pancake") configured as in FIG. 2A, the housing being circular and including a circular groove and a circular partition disposed within the groove. The same structure is illustrated in both FIGS. 2B and 2C, but FIG. 2B shows details of one side of the housing. In the example of FIGS. 2B - 2C, the magnet 200 includes a housing 202 that includes an upper plate 203, a lower plate 204, and partitions 210, 212, and 214. The magnet further includes an inner joint 206 and an outer joint 208.

[0039]

[0055] ​In the examples of FIGS. 2B and 2C, the magnet 200 includes three structural partitions 210, 212, and 214. According to some embodiments, these partitions may reduce the circumferential strain that accumulates in the HTS tapes on multiple windings when exposed to high Lorentz forces. As shown in FIGS. 2B - 2C, the structural partitions 210, 212, and 214 are received in slots or grooves formed in the upper structural plate 203 and the lower structural plate 204. The radial positions of the slots and their associated structural partitions 210, 212, and 214 may be determined by computer analysis, such that the tape strain during operation that accumulates does not exceed the allowable range. Conversely, the number of partitions can be minimized, so that the space within the housing is not taken up by an unnecessary number of partitions, which otherwise could be occupied by the HTS tapes. The spaces between the partitions where the HTS tapes can be disposed, i.e., spaces 220, 222, 224, and 226 in the examples of FIGS. 2B and 2C, may sometimes be referred to hereinafter as "channels".

[0040]

[0056] In the examples of FIGS. 2B and 2C, each structural partition 210, 212, and 214 has a through - connection slit for transitioning the tape stack radially from one side of the partition to the other side. Explanatory examples of suitable through - connection slit structures are described below. Thus, as shown in FIGS. 2B and 2C, at least one of the pancakes in the magnet assembly may include a plurality of channels separated by one or more partitions to withstand radial loads, each channel having one or more windings of HTS tape, and each partition having a through - connection that connects the windings of the HTS tape in adjacent channels. Using this through - connection slit, a continuous single HTS tape or tape stack can be wound from the inner diameter to the outer diameter while passing through the partition but being structurally supported by the partition.

[0041]

[0057] It should be understood that the number of partitions in one pancake, and thus the number of channels in that pancake, can be adjusted. The reasons for such adjustments include, among other things, absorbing variations in the diameter of the pancake, the materials used in the fabrication of the pancake including the partitions themselves, the materials used in the HTS tape (or stack of HTS tapes), the magnitude of the designed material stress, the designed operating temperature, the magnetic field, and the technical current density (or transport current), and / or other suitable factors.

[0042]

[0058] FIG. 2D is a photograph of a magnet including partitions and an HTS tape, according to some embodiments. Magnet 280 is an example of magnet 200 including an HTS tape, with the upper structural plate removed, thereby allowing the interior of the magnet to be viewed. As shown in FIG. 2D, magnet 280 includes three partitions 286, 287, and 288. Each of the three partitions includes a through-connection slit (not clearly shown in FIG. 2D), and the HTS tape is wound from the interior of the magnet around central structure 285 (forming tape region 281), through partition 286, around partition 286 (forming tape region 282), through partition 287, around partition 287 (forming tape region 283), through partition 288, and around partition 288 (forming tape region 284). In the example of FIG. 2D, central structure 285 consists only of an inner diameter electrical junction, as described above.

[0043]

[0059] FIGS. 3A - 3C illustrate various configurations of through-connection slits in structural partitions, according to some embodiments. Each of FIGS. 3A - 3C illustrates a circular partition disposed within a circular slot in a structural plate. Note that although exemplary through-connection slits are illustrated for circular partitions and circular slots, it can be understood that the same type of slit design can be implemented in partitions of other shapes (such as rectangular), and / or in partitions not disposed in slots within the structural plate. It should be understood that although exemplary through-connection slits are illustrated for circular partitions and circular slots, the same type of slit design can be implemented in partitions of other shapes (such as rectangular), and / or in partitions not disposed in slots within the structural plate.

[0044]

[0060] In the example of FIG. 3A, the partition wall includes a partial slit configuration 310 in which the slit does not extend over the entire height of the partition wall. In the example of FIG. 3B, the partition wall includes a full slit configuration 320 in which the slit extends over the entire height of the partition wall. In the example of FIG. 3C, the partition wall includes a partial slit configuration 330 for a partition wall having a helix machined on its outer diameter, whereby the partition wall is not a pure circle but rather has a shape of approximately one full turn of a helix. The configuration of FIG. 3C may include a partition wall having a radially uniform thickness that can withstand radial loads equally in all azimuthal directions. FIG. 3C illustrates that the partition wall has a helix machined on its outer diameter but is circular at its inner diameter, although other suitable configurations for the partition wall may have a helical shape at both the inner and outer diameters. It should be understood that other slit configurations may also be used, particularly to reduce radial stress, in accordance with the concepts, techniques, and structural embodiments disclosed herein.

[0045]

[0061] As described above, the embodiments of this specification are not limited to circular partition walls disposed within circular slots, and may also be advantageous for configurations in which the partition wall is rotatable within the slot when winding the magnet. Since the azimuthal position where the tape needs to penetrate the partition wall may be unknown, the circular partition wall and circular slot configuration allow the partition wall to be rotatable during winding, such that the through-connection slit of the partition wall is disposed at the azimuthal position required when the tape fills all of the space inside the partition wall.

[0046]

[0062] As described above, in some embodiments, the high magnetic field superconducting magnet may be formed by winding HTS, HTS tapes, or HTS tape stacks disposed in a flat layer (e.g., the contact surface of the layer may be formed to be orthogonal to the central longitudinal axis of the magnet around which the layer is disposed), and such a configuration may be referred to as a "pancake winding" or more simply a "pancake". Thereby, the pancake includes both the HTS component and the structural component for housing the HTS. When the magnet is formed by a layer having a winding (e.g., the contact surface of the layer is formed to be parallel to the central longitudinal axis of the magnet around which the layer is disposed), such a configuration may be referred to as a "layer winding method" or simply a "layered configuration", and even more simply a "layered".

[0047]

[0063] Figure 4A is a cross-sectional view of a magnet assembly 400 according to some embodiments, and Figure 4B is a view showing an enlarged portion of the cross-sectional view. According to some embodiments, the magnet assembly 400 can be designed for use in high magnetic fields (e.g., 10 Tesla or more). According to some embodiments, the magnet assembly 400 can be composed of a plurality of pancake conduction-cooled "cold masses" having an outer diameter (OD) electrical junction 402 and an inner diameter (ID) electrical junction 404. In the embodiments described in detail herein, the mechanical structure (hereinafter "housing") of each pancake holding the HTS may be an austenitic nickel-chromium alloy such as Inconel® alloy by Special Metals Corporation of New Hartford, New York, USA, or a nitrogen-strengthened austenitic stainless steel such as Nitronic® alloy by AK Steel of West Chester, Ohio, USA, or steel, or other suitable structural conductors, or may include them. However, it should be understood that in other embodiments, the housing may be formed of other structural materials that may or may not be conductors. In the example of Figure 4, the magnet assembly 400 uses a cooling device with a terminal 408 that is electrically insulated from the magnet assembly by an electrical insulator 406 (such as a high-pressure fiber glass laminate) to transfer heat by conduction or remove it in other ways.

[0048]

[0064] Although the examples of Figures 4A-4B illustrate a specific non-insulated pancake design, many of the features and manufacturing techniques disclosed herein are applicable to magnets formed by wholly or partially insulated HTS tapes or tape stacks, and those skilled in the art will understand how to adapt the concepts, techniques, and structures taught herein to wholly or partially insulated designs. For example, the magnet assembly does not need to include the same number of septa in each pancake, and does not need to include pancakes at the same radial position in each pancake as shown in the examples of Figures 4A-4B.

[0049]

[0065] Figure 4B shows an enlarged portion of the cross-sectional view of Figure 4A. In the example of Figure 4B, the magnet assembly 400 includes two types of pancakes, referred to herein as "regular" pancakes and "end" pancakes. The regular pancakes 410, 412, 414, 416, 418, 420, 422, and 424 can each be formed of a pair of structural plates having a structural partition therebetween. Those partitions define a plurality of channels for holding one or more windings of HTS tape or tape stacks, and generate a magnetic field when a current is applied. (The HTS tape stack is not shown in Figures 4A - 4B to make the structure of the pancake itself more visually clear. That is, only the housing is shown).

[0050]

[0066] In the example of Figure 4B, the pancake 410 includes three partitions 425, 426, 427 extending outwardly from the inner diameter, and this partition design is replicated in the other regular pancakes of the stacked magnet assembly 400. The windings of the HTS stack form a continuous helix in the channels of each pancake, electrically connecting its inner diameter to its outer diameter. According to some embodiments, at least one HTS tape of the pancake may include a rare earth copper oxide such as REBCO. It should be understood that other superconducting materials may be used within the magnet assembly 400 to generate a magnetic field in accordance with the concepts, techniques, and structural embodiments disclosed herein.

[0051]

[0067] According to some embodiments, the HTS tape within the magnet assembly 400 and the material to be co-wound can be self-supporting and densely mounted in a pancake structure, whereby one or more windings of the HTS tape stack in each of the channels substantially fill the volume of the channel. Alternatively, at least one HTS tape of the pancake is soldered to at least one of the plurality of channels and soldered to one or more joints. It should be understood that other methods may be used to fix the superconducting tape or tape stack within the magnet assembly 400 according to the concepts, techniques, and structural embodiments disclosed herein.

[0052]

[0068] According to some embodiments, in order to enhance the stability of quenches due to small resistive heating in the joints, potential excessive strain and / or stress of the tape in the joints, and inter-channel transition through the structural septum in each pancake, copper co-winding can be added in those critical regions. To reduce the temperature rise associated with quenches due to induced pickup eddy current heating of the copper component in the joints, current leads, and inter-channel transitions, the HTS tape stack can be reinforced by adding series HTS tapes that achieve a larger current-carrying capacity. Further, to reduce the potential twist of the HTS tape stack in the joints, current leads, and inter-channel transitions, the HTS tape stack can be reinforced by co-winding with a steel tape. Additional co-winding may be added. For example, copper co-winding can be added to improve normal conduction propagation through the septum during a quench or for other purposes.

[0053]

[0069] According to some embodiments, each of the pancakes of the magnet assembly 400 may include one or more joints for electrically coupling one or more windings of HTS tape as part of an electrical circuit. More specifically, ring-shaped joints embedded in the structural plate may be located at the inner and outer diameters of each regular pancake and terminate the superconducting electrical path. These joints may include and / or be composed of copper and / or other conductive materials and / or may include and / or be composed of superconducting materials. By way of example, the regular pancake 422 has an inner diameter joint 440 and an outer diameter joint 442. The helix of the HTS tape stack continues into the grooves of those joints. In an exemplary embodiment, the helix may terminate after a plurality of complete 360-degree rotations, and in other embodiments, the groove may terminate before or after one complete rotation.

[0054]

[0070] According to some embodiments, the inner diameter joint 440 and the outer diameter joint 442 may each be embedded in the structural plate of each pancake, thereby being in the same plane as the plane of the structural plate or extending slightly above it on its opposite side. In particular, the joint may extend above the structural plate in order to provide adjacent space for the cooling plate, as described below. According to the modular design disclosed herein, the number of regular pancakes can be any number of one or more in order to generate a desired magnetic field.

[0055]

[0071] In the example of FIGS. 4A and 4B, a plurality of identical pancake-shaped elements can be stacked together with alternating axial orientations in channels filled with HTS tape. This arrangement can provide a continuous electrical path between the exposed joints of the two outermost pancakes, through the helix of the HTS tape and between the mated ID and OD joints of all the pancakes of the magnet assembly 400. Specifically, one of the pancakes is electrically coupled by its outer diameter joint to the joint on the outer diameter of a second one of the pancakes, and the first pancake is electrically coupled by its inner diameter joint to the joint on the inner diameter of a third one of the pancakes, and an alternating housing pattern can be repeated. As an example, in FIG. 4B, the outer diameter joint of the first pancake 412 and the outer diameter joint of the second pancake 414 are mated via an electrical coupling region 446, and the inner diameter joint of the first pancake 412 and the inner diameter joint of the third pancake 410 are mated via an electrical coupling 444. To facilitate better electrical contact between the joints between pancakes, a conductive (e.g., indium) gasket may be inserted between the respective mating surfaces of the joints of two adjacent stacked pancakes during manufacture.

[0056]

[0072] Note that in FIG. 4B, it should be noted that the coupling region 446 includes a portion of the cooling plate 452 inserted between the joints in pancakes 412 and 414. In the exemplary magnet assemblies of FIGS. 4A and 4B, the outer joints between the plates contact only half of the pancake, and the other half has a cooling plate inserted between the pancakes. This difference is apparent when comparing the left joint region 402 in FIG. 4A showing the joints in contact with each other, and the right joint region 402 in FIG. 4A showing the joints with a cooling plate therebetween.

[0057]

[0073] In the examples of FIGS. 4A and 4B, the electrical path of the winding of the HTS tape is completed by the outermost two end pancakes 430 and 432. The end pancakes 430, 432 present an integrated structural plate having a single ring-shaped junction located at either the ID or OD at the same radial position as the standard pancakes that are in electrical contact. That is, each of the top pancake of the stacked plates and the bottom pancake of the stacked plates has an inner surface with a junction at either its outer diameter or its inner diameter that is electrically coupled to the junctions of the other (standard) pancakes, and a parallel outer surface without a junction.

[0058]

[0074] In the examples of FIGS. 4A and 4B, both end pancakes 430, 432 have their respective junctions 434, 436 at the OD, but only on their inner surfaces. The ring-shaped junctions 434, 436 of the end pancakes 430, 432 are continuously connected to conductive plates of the same conductor and extend radially outwardly, typically in the direction of the HTS current leads (e.g., conductor 406 as shown in FIGS. 4A and 4B). The HTS tape stack starts inside the ring of the junction, forms a 360-degree loop in the groove of the junction, and then enters and fits into the groove of the extension plate. Thereby, each of the pancakes (both standard and end) is electrically coupled by its one or more junctions to the junctions of either one or two nearby pancakes, thereby forming an operating current path including the HTS tape in each of the pancakes.

[0059]

[0075] According to some embodiments, although it was described above that the ID and OD junctions are implemented in the shape of a continuous circular ring, the junctions may alternatively be configured as discontinuous plates, formed as extensions from their respective pancakes, positioned around the pancakes, and thereby fitting in the assembly and, as described above, may be pressed and fixed individually in the cold mass assembly, or one junction at a time, or all together.

[0060]

[0076] According to some embodiments, the pancakes are independent of each other and are only connected for electrical operation in the assembly, so the shape of each individual pancake can be different as long as the mating surface of the adjacent pancake assemblies is available. Generally, the cold mass and the HTS windings can be shaped as a solenoid or a racetrack, or can have different shapes that topologically match either of them. Thus, at least two of the pancakes may have different sizes or different shapes. It is expected that those skilled in the art can come up with other sizes or shapes without departing from the concepts and techniques disclosed herein.

[0061]

[0077] According to some embodiments, the cold mass may be conduction cooled by a thermally conductive (e.g., copper, aluminum, silver, gold, graphite, etc.) cooling plate inserted between the pancakes in the space not yet filled by the assembly. In the examples of FIGS. 4A and 4B, the copper cooling plate 450 is disposed between adjacent regular pancakes 422 and 424, and this design of alternating pancakes and cooling plates is repeated throughout the magnet assembly 400 as shown. In some embodiments, the copper cooling plate may be electrically insulated to prevent electrical short circuits between the pancakes. This insulation can be achieved by coating each surface with a layer of an electrical insulator such as polytetrafluoroethylene (PTFE) or the like and solidifying the insulator. It should be understood that other coatings may also be used.

[0062]

[0078] Each of the copper cooling plates 450 may be thermally conductive and may be arranged to pass from between the pancakes to the terminals through a layer of electrical insulator in order to thermally couple the cooling plate to the cooling device. In the examples of FIGS. 4A and 4B, the copper cooling plate 450 has a terminal 452 that is in thermal contact with the terminal 470 of the cooling device. In this way, each of the pancakes is adjacent to either one or two of the cooling plates, enabling the pancake to be cooled to its operating temperature and enabling the pancake to transfer heat generated in the pancake to the cooling device by thermal conduction. Specifically, each end pancake is adjacent to one of the cooling plates, and each standard pancake is adjacent to two of the cooling plates.

[0063]

[0079] According to some embodiments, when the HTS penetrates the through-connection slit of the structural partition, additional material other than the HTS tape may be supplied to fill any gaps in the through-connection. This additional material may reduce tape degradation caused by deformation induced by pressure and / or other forces during magnet operation. The HTS in the slit tape may be relatively thin and thus may be particularly susceptible to the effects of deformation, and such deformation can be avoided by adding a "shimming" material placed in the through-connection.

[0064]

[0080] FIG. 5 is a photograph of a through-connection slit with a shim in addition to the HTS tape, according to some embodiments. In the example of FIG. 5, the upper plate is removed, and a magnet is shown with the HTS tape wound inside and between the partitions as described in the various embodiments above. In the example of FIG. 5, the partition 520 separates the HTS tape winding region 512 from the HTS tape winding region 511, and this HTS tape penetrates the slit of the partition 520. In the example of FIG. 5, the partition 520 is of the type shown in FIG. 3C, and this partition has a helical shape with approximately one full turn. Additional shimming materials 522 and 523 are inserted on either side of the partition to fill gaps that may otherwise appear when the winding of the HTS tape 518 passes through the partition 520.

[0065]

[0081] The shimming materials 522 and 523 may include additional pieces of HTS tape and / or additional strips of conductive material (e.g., copper strips and / or steel strips). Multiple strips of various materials may be inserted as needed (e.g., multiple strips of HTS tape, multiple strips of copper tape, and multiple strips of steel tape may all be inserted together as a single shim or “co-wound”).

[0066]

[0082] FIG. 6 is a flowchart of a method of assembling a magnet according to some embodiments. For purposes of illustration, method 600 will be described in connection with the exploded assembly view of a magnet as shown in FIG. 7, but it should be understood that method 600 is not limited to the assembly of a magnet using the specific components of FIG. 7. In particular, FIG. 7 illustrates a circular partition and a circular structural plate having circular slots, but method 600 may be practiced using partitions and plates of any suitable shape (plates without slots or plates including non-circular slots).

[0067]

[0083] With respect to the elements of FIG. 7, the figure shows an exploded assembly view of the structural and electrical components in a complete standard pancake 500, such as the magnet assembly 400 shown in FIGS. 4A and 4B, or the pancake included in the magnet 200 of FIGS. 2B and 2C. The design shown in FIG. 7 facilitates a convenient process for making a pancake and winding an HTS tape stack around the structural plate of the pancake. The HTS tape stack may be a tape stack as described above in connection with FIGS. 4A and 4B. The manufacture of the end pancakes is similar, and the differences will be pointed out below.

[0068]

[0084] The pancake can be assembled by first installing and bolting the inner diameter joint 720 below the structural plate 710. The HTS stack may be pre-soldered in the grooves in the ID joint 720, or optionally, soldered in place after installation of the joint in operation 602. At this stage in the assembly process, the radial space outside the ID joint 720 is open, and in particular, there are no partitions installed in the slots of the lower structural plate 710.

[0069]

[0085] In operation 604, the stacked HTS tape can then be wound outward from the ID joint 720 in a single plane, i.e., in the same manner as the tape is wound around the cassette reel. The winding of the HTS tape from the reel to the pancake produced by this "inter-reel" technique greatly simplifies the winding process. The winding continues until the deposited radial structure reaches the slot 712 of the first partition 730.

[0070]

[0086] Optionally, the first partition 730 may not be fixed to the lower structural plate 710 but may be insertable during the winding process. In such a case, the partition is inserted into the first partition slot 712 at an appropriate timing during the winding of the HTS tape around the ID joint 7 20. In such a case, the partition 730 may be inserted into the slot 712 of the lower structural plate 710, thereby minimizing the gap between the tape and the partition 730 as much as possible. In the case of a circular (tubular) winding, this is achieved by rotating the partition 730 to the best azimuthal position for minimizing the above gap, i.e., the position where the circumferential winding of the HTS tape just reaches the slot 712 in operation 608 for placing its through connection.

[0071]

[0087] In operation 610, the HTS tape stack, which reduces the formation of kinks in the transition region for any of the above-described local co-wound materials (e.g., copper, steel, and / or HTS tape), may be driven through the gap in the septum 730 to the outer diameter of the septum 730, and then the septum 730 is rotated within the slot 712 and the tape is fed through the through connection until the volume inside the septum 730 is entirely filled with tape. At this time, the septum 730 is held in place and the "inter-reel" winding continues around the outside of the septum 730.

[0072]

[0088] According to some embodiments, the first septum 730 and the other septa 740 and 750 include a through connection slit through which the HTS tape stack passes, as shown in any of FIGS. 3A, 3B, or 3C, or using other configurations having through connections.

[0073]

[0089] The processes of operation 604 and optionally operation 606, and operations 608 and 610 may be repeated for each of the septa 730, 740, and 750 until the winding reaches the position of the outer diameter joint 760. After its installation, the HTS tape stack (with co-winding) is inserted into the gap in the OD joint 760 and soldered. The potential gap between the winding and the septa 730, 740, 750 or the joints 720, 760 may be filled with shims made of copper or steel pieces or may be composed of one or more thin tape shims. Thus, the interior of each regular pancake may be monolithic and the HTS tape stack is fixed in place against the radial force.

[0074]

[0090] According to some embodiments, each of the partition walls 730, 740, 750 may extend above the top of the HTS tape winding, i.e., the partition walls 730, 740, 750 may have a height slightly exceeding the wound HTS tape. In such a case, a layer of indium may be added to the space above the wound HTS tape before being finally covered by the upper structural plate. Finally, the upper structural plate 770 is installed in the same plane as the top of the HTS tape, the partition walls, and the assembly. During installation, the partition walls 730, 740, 750 are inserted into slots on the lower side of the upper structural plate 770 that are in the same radial position as the slots 712, 714, 716 of the lower structural plate 710, thereby providing support to the partition walls against the radial forces accumulated during operation.

[0075]

[0091] Fabrication of the end pancakes may include insertion of the OD assembly 760 and the copper expansion plate, and soldering of the HTS tape stack into the grooves of the assembly.

[0076]

[0092] Accordingly, a housing for holding a wound tape for generating a magnetic field is disclosed. The housing includes a first structural plate 710 having one or more first circular slots 712, 714, 716. The housing further includes one or more partition walls 730, 740, 750, each of such partition walls having a through connection for winding a tape from the inner diameter to the outer diameter of the partition wall. Each partition wall 730, 740, 750 is insertably and rotatably inserted into a corresponding slot among the first circular slots. That is, since the slots are circular and the partition walls are designed to be received within the slots, the partition walls are advantageously rotatable within each slot, whereby their through connections have a desired azimuthal position, facilitating the winding, i.e., in the slots Rotate the through-connection so that the entire volume inside the partition is securely filled with tape. The housing further comprises a second structural plate 770 having one or more second slots, and each partition is insertably inserted into a corresponding slot among the second slots. One of the partitions 730, 740, 750 may have a through-connection slit according to any of the configurations 310, 320, or 330 shown in FIGS. 3A - 3C, or any other configuration that facilitates passing a tape wound from one side of the partition to the other side.

[0077]

[0093] That is, a method of winding a conductive tape to form a magnet is disclosed. Method 600 includes providing a first structural plate 710 having a surface with one or more circular slots 712, 714, 716 and having a first electrical junction 720 at its inner diameter. The method then optionally includes operation 602 in which a conductive tape is physically and electrically coupled to the first electrical junction 720. The method proceeds to operation 604 where the conductive tape is wound circularly on the surface of the first structural plate 710 until it reaches one of the circular slots (e.g., circular slot 712). Next, the method optionally includes operation 606 in which a partition (e.g., partition 730) having a through-connection slit is insertably inserted into one of the circular slots 712, where the partition 730 may optionally be rotated inside one of the circular slots 712 such that its through-connection is aligned with the azimuthal position of the wound conductive tape. The method proceeds to operation 608 where the HTS tape is aligned with the through-connection (by rotating the partition or otherwise), and then, in operation 610, the conductive tape is wound around the outer diameter of the partition 730 through the through-connection on the surface of the first structural plate 710, thereby minimizing the gap between the conductive tape and the partition 730.

[0078]

[0094] The method may then repeat operations 604 - 610 for each additional slot of the one or more circular slots (e.g., using partitions 740 and 750 for additional circular slots 714 and 716 respectively). If the first structural plate 710 has a second electrical junction (e.g., junction 760) at its outer diameter, the method may include physically and electrically coupling a conductive tape to the second electrical junction 760. The method may further include adding a layer of indium adjacent to the wound conductive tape.

[0079]

[0095] In some embodiments, method 600 further provides a second structural plate (e.g., plate 770) having a surface with a second circular slot, and by arranging the second structural plate 770 in the same plane as the wound conductive tape, a partition (in this case, partition 730) is insertably inserted into the second circular slot, thereby creating a pancake having a complete structural housing and the wound tape. Note that the second structural plate may have slots for receiving additional partitions (e.g., partitions 740 and 750), and it should be understood that arranging the second structural plate 770 may further insert those additional partitions insertably into corresponding slots of the second structural plate. As described above, the conductive tape is co-wound with copper, steel, or both copper and steel.

[0080]

[0096] FIG. 8 is a perspective view of an end pancake 800 that can be used in a magnet assembly such as the magnet assembly 400 shown in FIGS. 4A-4B. The end pancake 800 includes a structural plate 802 and a single electrical junction 804 used to carry current between the magnet assembly via a conductor 806. The end pancake 800 is shown with the electrical junction 804 along its outer diameter. As described above, further, along its inner diameter, it is contemplated to provide an end pancake having a single junction used, for example, in a magnet assembly having an odd number of standard pancakes. Such an alternative end pancake may require a conductor radially outward from the inner diameter for connection to an external circuit, and those skilled in the art will likely understand how to fabricate such a conductor.

[0081]

[0097] The electrical path between consecutive pancakes alternates between the inner and outer diameters of the stack over its entire length, and thus there are two types of copper cooling plates shaped accordingly. Thus, FIG. 9 shows a copper cooling plate 900 used between pancakes that are fitted along its inner diameter as illustrated by an electrical coupling interface 910, such as the connection between pancakes 410 and 412 in the electrical coupling 444 as shown in FIG. 4B, as well as similar connections between pancakes 414 and 416, between pancakes 418 and 420, and between pancakes 422 and 424. In particular, the copper cooling plate 450 can be implemented as the copper cooling plate 900 of FIG. 9. It should be understood that in a design where the end pancake has a ring-shaped electrical junction along its inner diameter and mates with the standard pancakes, the copper cooling plate 900 or a plate of a similar design should be used at the interface.

[0082]

[0098] Similarly, FIG. 10 shows a copper cooling plate 1000 used between pancakes that are fitted along their outer diameter as illustrated by the electrical coupling interface 1010, such as the connection between pancakes 412 and 414 in the electrical coupling 446 as shown in FIG. 4B, as well as similar connections between pancakes 416 and 418, and between pancakes 420 and 422. In particular, the copper cooling plate 454 can be implemented as the copper cooling plate 1000 of FIG. 10. In the exemplary designs of FIGS. 4A and 4B where each of the end pancakes 430 and 432 has a single ring-shaped joint, the copper cooling plate 1000 can be used for the connections between pancakes 430 and 410, and between pancakes 424 and 432.

[0083]

[0099] Note that in a design with an odd number of standard pancakes, it should be understood that one end pancake has an electrical joint along its inner diameter and the other end pancake has an electrical joint along its outer diameter. In such a case, the first end pancake is adjacent to the copper cooling plate 900 and the second end pancake is adjacent to the copper cooling plate 1000.

[0084]

[0100] According to some embodiments, a heat conductive member can be inserted between one of the pancakes and an adjacent stacked cooling plate to enhance heat conduction when the magnet assembly is in a vacuum state and to facilitate cooling of the pancakes incorporating the HTS tape. By way of example, the heat conductive member can be indium foil, or an ultra-low temperature high vacuum grease such as Apiezon (registered trademark) N grease by M&I Materials Limited of Manchester, UK, or a mesh of conductive wires.

[0085]

[0085]

[0101] To complete the fabrication of the magnet assembly 400 shown in FIGS. 4A - 4B To this end, standard and end pancakes having a suitable number for the operating requirements are stacked together with the insulated copper cooling plates as described above, and the stack of pancakes using the intermediate cooling plates can be connected together by bolts at both its inner diameter and its outer diameter. Optionally, the magnet assembly 400 includes additional structural plates 480, 482 at the top and bottom of the stack, which are bolted to each other, and the stacked plates are instead (or additionally) pressed together by those additional structural plates 480, 482. At a later point in time, the magnet assembly 400 can be disassembled by removing the tightening bolts to separate the individual pancakes. Thereafter, if necessary, the cold mass can be reassembled using more or fewer standard pancakes to achieve different operating magnetic fields. Thus, the design of the magnet assembly 400 is advantageously both modular and conduction-coolable, facilitating assembly and disassembly, and it should be understood that the use of 10 pancakes and 9 cooling plates in the embodiments shown in FIGS. 4A and 4B is merely an example.

[0086]

[0102] Thus, a magnet assembly 400 is disclosed that includes a plurality of cooling plates, of which cooling plates 450 and 454 are examples and each of the cooling plates has a terminal (e.g., terminal 452) for thermally coupling the cooling plate to the cooling device 470. As shown in FIGS. 4A and 4B, a plurality of pancakes and a plurality of cooling plates are alternately arranged in a stack, and each of the pancakes in the stack is electrically coupled by one or more joints to a joint of one or two adjacent pancakes in the stack, thereby forming an operating current path through the stack including HTS tape in each of the pancakes, and each of the pancakes is thermally coupled to one or two of the cooling plates adjacent thereto.

[0087]

[0103] Regarding the operation of the magnet assembly 400, the operating current is at a given It can be defined by the energization capacitance of the HTS tape stack specialized for the operating temperature and maximum magnetic field. Since the peak magnetic field varies between windings, optionally, the slope of the HTS tape stack may be brought about by changing the number of tapes in the stack. This helps in reducing the total amount of tape in the magnet assembly 400. For the sake of explanation, since the magnetic field is high at the ID and low at the OD, the critical current of the HTS tape is lower for the inner diameter (ID) than for the outer diameter (OD). To compensate for that difference, more tapes are required at the ID, i.e., the HTS tape stack is "sloped". This is achieved by starting the winding at the ID with the maximum required number of tapes and then terminating some of the tapes at a given radial position, which can be done in the winding process as described above. Note that this simplified explanation does not clarify the cause of the dependence of the critical current on the direction of the magnetic field with respect to the tape surface, but it should be noted that it is sufficient for the present disclosure.

[0088]

[0104] To operate the magnet assembly 400, there are several nominal modes, together with an uncontrolled quench, charging, steady state, low speed and high speed discharging. Each of those modes will be described below.

[0089]

[0105] The charging and low speed discharging modes are controlled by an external power source (not shown) for the transport power It is performed by changing the current. Different from the conventional magnet wound with an insulated cable, the charging of the non-insulated magnet takes a very long time and is driven by the induced voltage-driven inter-turn current sharing and the resulting heating. The faster the charging rate dl / dt, the stronger these radial currents become, and in order to avoid the temperature rise of the cold mass structure and the HTS tape, a larger resistive heating power accumulated inside the structure needs to be removed by conduction cooling. To speed up the charging, in this magnet assembly 400, the charging rate can be controlled and dynamically adjusted to maintain the temperature measured at the warmest position (i.e., the position farthest from the cooling source) at the highest allowable value. The highest allowable temperature is defined by the approximation of the transport current to the critical current with respect to the combination of the peak magnetic field and temperature.

[0090]

[0106] The heat loss in the steady-state mode operation at a given constant current is very small and is easily managed by the available cooling power of the cooling source described in connection with FIGS. 1A and 11B. 1A and FIGS. 11B.

[0091]

[0107] Fast discharge is used to drive the current and magnetic field of the magnet assembly 400 to zero in an emergency situation. This is achieved by opening the current supply circuit. This operation tends to trigger strong induced eddy currents in the outermost winding in the radial direction of the outermost pancake in the axial direction and protect the magnetic flux in the magnet assembly 400. The outer diameter joint 402 forms a convenient circuit path for those currents and promotes substantially uniform heating along the edge of the winding. This heat line propagates deeper radially within the magnet assembly 400 and quenches the HTS tape windings one by one until the entire pancake is quenched. At this time, most of the transport current changes its path from the path along the azimuth of the helical HTS tape winding to the path between the structural plate and the HTS tape itself (e.g., in Indiana, USA The magnetic flux lost from the quenched pancake is picked up by the next pancake, triggering a similar process therein. This process continues until the entire pancake is quenched, and all the stored electromagnetic energy is accumulated in the cold mass in the form of heat.

[0092]

[0108] The advantage of this method of quenching the magnet is that the quench is initiated and predictable. The advantage of this method is that the quenching current propagates very uniformly and does not form localized overheating points. This is achieved essentially due to the joints forming a path for the induced current. The quenching time depends on the size of the magnet assembly 400 and is expected to be very fast, less than one second. This differs from insulated magnets known in the field of the invention, which are quenched by dumping the current through an external resistor. In this case the quenching time is defined by the terminal voltage and is usually very long. The salient feature of a quench in a non-insulated magnet is the low voltage, on the order of 1 V or less, generated between the components comprising the magnet. This feature significantly reduces the requirement to insulation and allows the use of the insulation techniques mentioned above.

[0093]

[0109] Uncontrolled quenching occurs when, for some reason, the transport current exceeds the critical current. This usually occurs due to the local formation of a quench initiation zone. In non-insulated magnets, including the present design, this situation locally radially redistributes a portion of the series winding current, thereby changing the magnetic flux distribution and creating conditions similar to those described above for emergency shutdown with controlled quench. Copper cladding in the form of copper joints serves a similar purpose and in the present design leads to a more controlled quench propagation, resulting in more uniform Joule heating. Alternatively, with sufficient cooling power, the normal conduction band can return to a superconducting state.

[0094]

[0110] According to some embodiments, the cold mass of the magnet assembly is adiabatic It may be surrounded by a vacuum and enclosed in a cryostat, with a thermal radiation shield inserted between the cryostat walls and the cold mass. Conduction cooling may be achieved by cryocoolers, cryo-refrigerators, heat exchangers utilizing a continuous flow of cryogenic liquid, or other conventionally used techniques. In general, however, the cooling device acts as a heat sink for the thermal energy generated in the cold mass. Additionally, the cooling device, together with its thermal insulation, provides cooling of the magnet's cold mass to an operating temperature, facilitates charging / discharging of the magnet assembly, and provides physical support for the magnet assembly during operation and, if necessary, during transportation.

[0095]

[0111] In this regard, FIG. 11A illustrates a magnet coupled to a portion of a cooling device 1110. 11B is a cutaway view of magnet assembly 1100, and FIG. 11B is a view of portion 1110 highlighting different thermally protective layers surrounding magnet assembly 1100. Magnet assembly 1100 may be, for example, magnet assembly 400 of FIGS. 4A and 4B.

[0096]

[0112] Thermal insulation can be achieved in several forms. The first form is e.g. -4 Torumi The first involves pumping the cryostat to an adiabatic vacuum, which can be at full pressure. The second involves placing a thermal radiation shield 1120 around the cold mass that is cooled to some intermediate temperature between the cryostat wall temperature and the cold mass temperature. The third involves encasing the cold mass and radiation shield 1120 in a multi-layer insulation (MLI) 1130, shown in more detail in FIG. 11B.

[0097]

[0113] A radiation shield 11 surrounds the magnet assembly 1100 and the entire cold mass. 20 includes a thermally conductive metal, typically copper, having good thermal contact with an intermediate temperature source of cooling. This cooling source may be an individual cryocooler, or a first stage of a cryocooler that cools a magnet, or any other source of the required temperature and cooling power such as liquid nitrogen or cryogenic gas from a cryogenic refrigerator, or any combination thereof.

[0098]

[0114] At the position of the radiation shield 1120 and during a magnet quench in response to the fringe magnetic field and the rate of change of the magnetic field, the radiation shield 1120 may have a portion 1122 cut for electrical insulation in order to limit eddy currents in the material of the shield 1120 and further to limit the Lorentz force that interacts between the quenching magnet and the shield 1120. Such forces may deform or even break the radiation shield 1120. The thermally conductive material of the shield 1120 may be reinforced by a strong metal or non-metal structure for similar reasons.

[0099]

[0115] A quench generation time of very high speed and less than one second is specific to the non-insulated coil disclosed herein. At this time, the coil current and the high magnetic field generated by this current change from their operating values to zero. These changes may, as a result, generate strong Lorentz forces in the radiation shield 1120 and are very powerful, so the general means similar to those described above are not sufficient to protect the integrity of the shield 1120 during quenching.

[0100]

[0116] Referring now to FIG. 11B, in the disclosed cooling device, the radiation shield 11 To reduce and limit the eddy currents and forces acting on the 20, the conductive material (e.g., copper) of the radiation shield 1120 is cut into narrow strips at least in part 1122. The size of these strips is determined by the acceptable force on the structure of the shield 1120. The strips in part 1122 are electrically insulated from each other. As an example, the strips can be implemented as 10 mm wide copper strips with an insulation gap of 0.5 - 1.0 mm between them. The strips are coupled to a shield structure 1124 placed below that can be formed of a non-conductive material such as fiberglass G11-CR. Alternatively, if the forces generated during quenching allow, the underlying shield structure 1124 can be formed of a low-conductivity but strong metal such as stainless steel.

[0101]

[0117] The coupling of the copper strips in part 1122 to the structure 1124 of the shield 1120 can be achieved by adhesion, riveting, or screwing. An electrical insulation film can be used to insulate the copper strips from the stainless steel body if present. Any strips attached to the radiation shield 1120 parallel to the top and bottom faces of the magnet assembly 1100 need to be coupled to the outer surface of the shield structure. During quenching, at this position, the strips are pushed towards the magnet assembly 1100 by the shield structure.

[0102]

[0118] At least a part of the radiation shield 1120 is located away from the magnet assembly 1100, and the level of the magnetic field allows for the normal design of the shield (i.e., not cut by the strips). The thermally conductive copper strips are coupled to the thermally conductive part of the shield by the application of indium shims or Apiezon (registered trademark) N grease to reduce the thermal resistance of the joints in the surrounding vacuum.

[0103]

[0103]

[0119] As a variant, the radiation shield 1120 is a printed copper strip of the required shape It can be formed as a fiberglass dashboard having it. Similar circuit boards can be used to wire the instrumentation lines.

[0104]

[0120] In some embodiments, to reduce the heat load on the shield due to the temperature drop and heat transfer from the warm cryostat wall, the radiation shield 1120 is encapsulated by a multilayer insulation (MLI) 1130. The MLI 1130 is used for insulation in a vacuum environment with a reduced pressure of 10 to 10 -5 torr for the good thermal performance of the cryostat. The MLI 1130 consists of alternating layers of a low emissivity radiation shield and a low thermal conductivity spacer material. The most commonly used low emissivity radiation shield is a Mylar® substrate having an aluminum coating vacuum deposited on one or both sides of the sheet. The spacer material can vary widely and is most commonly polyester. The blanket of the MLI 1130 may consist of many layers, such as 32 layers for example, and in many cases two blankets are used for better insulation of the shield. -7 The thickness of the deposited aluminum is very small, such as 350 angstroms, i.e.,

[0105]

[0121] 3.5 * 10 mm, etc. In this example, the total thickness of the aluminum in the blanket having 32 layers with double aluminum treatment is 0.00224 mm. At the same time, the deposited material may be very high purity aluminum (according to the expression used in the publication) having a residual resistance ratio (RRR) of approximately 1000 or more. The RRR is the ratio of the resistance of the material at room temperature and at a very low temperature of about 20 K. These characteristics mean that at the operating temperature of the radiation shield 1120 of 60 - 80 K, the combined effect of eddy currents in the MLI blanket during a quench of a non - electrically insulated magnet can generate a significant force applied to the radiation shield 1120, which is wrapped by the blanket of the MLI 1130. This force may damage the radiation shield and may further damage the MLI 1130. -5 ​

[0106]

[0122] For a high magnetic field, non - electrically insulated magnet cooling device, the deposition of aluminum on the Mylar film (or a film of other material) of MLI1130 is carried out with barriers located at different places on both sides of the aluminum - treated film. Those narrow barriers provide the electrical insulation necessary when splitting the aluminum - treated layer into strips. During a magnet quench, those barriers limit the eddy currents in the aluminum - treated film and reduce the Lorentz force applied to the shield 1120 to an acceptable level. At the same time, the thermal performance of MLI1130 is not significantly degraded. This is due to the tiny surface area of the barriers in the aluminum film and the absence of transparent places in the double - aluminum - treated film.

[0107]

[0107]

[0123] The above description is premised on the cold mass being cooled using a dry conduction cooling method. Alternatively, the cold mass may be cooled by a cryogen storage method, in which case it is surrounded by a sealed - structure case containing cryogenic liquids such as helium, neon, argon, hydrogen, etc. In the latter case, those skilled in the art will understand how to modify some of the above - described features to implement this change in the cooling device design.

[0108]

[0108]

[0124] For purposes of illustration, FIG. 12 is a cross - sectional view of an exemplary coated conductor HTS tape layer according to some embodiments. The following description is applicable to the above - described HTS tape disposed within a magnet or magnet assembly in some embodiments. Rare - earth barium copper oxide ( "REBCO") is a ceramic - based HTS. Ceramic - based HTS was first discovered in 1987, but the large - scale manufacture of REBCO HTS conductors has only been possible relatively recently due to the difficulty in manufacturing long REBCO strands that maintain high performance.

[0109]

[0109]

[0125] FIG. 12 is an example of an HTS tape 1200 fabricated as a coated conductor, H TS layer 1210 is a REBCO layer. As described above, "REBCO" is an acronym for "rare-earth barium copper oxide". When used herein, at least in some cases, "REBCO" may be used to more generally refer to any rare-earth copper salt H TS. Thus, unless otherwise specified, barium may be present in REBCO, but its presence is not essential. However, in the example of FIG. 12, the REBCO layer is provided as an example of an HTS layer, and there is no intention to limit the illustrated structure to the use of a specific HTS.

[0110]

[0126] In the example of FIG. 12, exemplary tape 1200 further includes a buffer layer 1212 and a Hastelloy® layer 1214, and copper layers 1216 and silver layers 1218 disposed on both the top and bottom of the REBCO layer, respectively. This copper layer may sometimes be referred to as a "stabilizer" layer. Exemplary dimensions of the tape are shown in FIG. 12, and the tape has a width (size in the X direction) of approximately 2 to 12 mm and a thickness (size in the Y direction) of approximately 0.1 mm.

[0111]

[0127] In some embodiments, the HTS tape may have an aspect ratio (the ratio of the width of the tape to its thickness) that is 10, 20, 40, 60, 80, 100, 120 or 150 or more. In some embodiments, the HTS tape may have an aspect ratio that is 150, 120, 100, 80, 60, 40, 20 or 10 or less. Any suitable combination of the ranges mentioned above (e.g., an aspect ratio of 60 or more and 100 or less) is also possible.

[0112]

[0128] In some embodiments, the HTS tape is 0.005 mm, 0.01 mm, It may have a thickness of 0.05 mm, 0.1 mm, 0.15 mm, or 0.2 mm or more. In some embodiments, the HTS tape may have a thickness of 0.5 mm, 0.2 mm, 0.15 mm, 0.1 mm, 0.05 mm, or 0.01 mm or less. Any suitable combination of the ranges mentioned above (e.g., a thickness of 0.01 mm or more and 0.1 mm or less) is also possible.

[0113]

[0129] FIG. 13 is a three-dimensional graphic of a power plant with a broken-away portion showing various components of a fusion power plant according to some embodiments. The fusion power plant may include a magnet or magnet assembly fabricated as described above. FIG. 13 shows a cross-section of the power plant and includes a magnet coil 1314, a neutron shield 1312, and a core region 1311. According to some embodiments, the magnet coil 1314 may be, or may form part of, a toroidal field coil. In some embodiments, the magnet coil 1313 may be fabricated from a superconducting magnet fabricated as discussed and described above, or may be included in some other manner. According to some embodiments, the magnet coil 1313 may be, or may form part of, a central solenoid and / or other poloidal field solenoid winding coil.

[0114]

[0130] One of ordinary skill in the art will recognize other embodiments of the concepts, results, and techniques disclosed herein. can be recognized. It is recognized that superconducting magnets configured by the concepts and techniques described herein can be beneficial for a wide range of applications. For example, one such application is to perform nuclear magnetic resonance (NMR) studies on, for example, condensed matter physics, physiology, or proteins. Another application is to perform clinical magnetic resonance imaging (MRI) for medical scanning of an organism or a part thereof where a small high-field magnet is required. Still another application is high-field MRI where a large-bore solenoid is required. Yet another application is for performing magnetic studies in physics, chemistry, and materials science. Further applications are particle accelerators for material processing or investigation, generators, generally medical accelerators for proton beam therapy, radiation therapy, and radiation generation, superconducting energy storage, magnetohydrodynamic (MHD) generators, and magnets for material separation such as mining, semiconductor fabrication, and recycling. Note that the above listing of applications is not exhaustive, and there are additional applications where the concepts, processes, and techniques disclosed herein can be applied without departing from their scope.

[0115]

[0131] As used herein, the term "HTS material" or "HTS superconductor" refers to a superconducting material having a critical temperature above 30°K at zero self-field.

[0116]

[0132] Thus, some aspects of at least one embodiment of the present invention have been described but it should be understood that various modifications, corrections, and improvements will readily occur to those skilled in the art.

[0117]

[0133] Such modifications, corrections, and improvements are intended to be part of this disclosure, It is intended to be within the spirit and scope of the present invention. Further, while the advantages of the present invention are shown, it should be understood that each embodiment of the technology described herein does not necessarily include each of the advantages described. Some embodiments may not implement any of the features described herein as being advantageous, and in some instances, one or more of the features described may be implemented to achieve further embodiments. Accordingly, the above description and drawings are merely examples.

[0118]

[0134] In the above detailed description, various features of the embodiments are grouped together in one or more individual embodiments for the purpose of streamlining the disclosure. The method of the present disclosure should not be construed as reflecting an intention that the claims require more features than those expressly stated in this specification. Rather, novel aspects may exist with fewer features than all of the features in each of the disclosed embodiments.

[0119]

[0119]

[0135] The above-described embodiments of the technology described herein may be implemented in any of a number of ways. Various aspects of the present invention may be used alone, in combination, or in various configurations not specifically described in the embodiments above, and thus are not limited to the details and component configurations described in the above description or shown in the drawings for their use. For example, aspects described in one embodiment may be combined with aspects described in other embodiments in any manner.

[0120]

[0120]

[0136] Also, the present invention may be embodied as a method for which an example is provided. The order of the operations performed as part of the method may be determined in any suitable manner. Accordingly, embodiments may be constructed in which the operations are performed in an order different from that shown, and may include performing some operations simultaneously, even if shown as sequential operations in the exemplary embodiments.

[0121]

[0121]

[0137] Furthermore, some actions are described as being performed by a "user". . It should be understood that the "user" need not be a single individual, and in some embodiments, actions attributable to the "user" may be performed by an individual in combination with a team of individuals and / or computer-assisted tools or other mechanisms.

[0122]

[0138] The use of terms such as "first", "second", "third", etc. in a claim to modify an element of the claim does not alone imply any priority, precedence or order of one claim element over other orders or temporal orders in which the acts of the method are performed, but is used only as a label to distinguish one claim element having a particular name from other elements having the same name (for the purpose of the use of the terms denoting order).

[0123]

[0139] The terms "about" and "approximately" mean, in some embodiments, within ±2 0% of the target value, in some embodiments within ±10% of the target value, in some embodiments within ±5% of the target value, and in still some embodiments within ±2% of the target value, and can be used . The terms "about" and "approximately" may include the target value. The term "substantially equal" can be used to refer to 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 in still some embodiments within ±2% of each other.

[0124]

[0140] The term "substantially" means, in some embodiments, within ±20% of a comparative measurement, In some embodiments, it can be used to refer to a value within ±10%, in some embodiments within ±5%, and in still some embodiments within ±2%. For example, a first direction that is "substantially" perpendicular to a second direction forms an angle of 90° with the second direction within ±20% in some embodiments, within ±10% in some embodiments, within ±5% in some embodiments, and in still some embodiments within ±2% in some embodiments, and can refer to a first direction that forms an angle of 90° with the second direction within the specified range.

[0125]

[0141] Also, the syntax and terminology used herein are for the purpose of explanation and should not be regarded as limiting. The use of "comprising", "including", or "having", "containing", "accompanying", and their variations herein is intended to include additional items together with the items listed previously and their equivalents.

Claims

1. 1. A high temperature superconductor (HTS) magnet, comprising: a coil including an HTS material; a housing having at least a first partition; Equipped with The coil is disposed within the housing, a first bulkhead of the housing is positioned to separate the first portion of the coil from the second portion of the coil such that the turns of the first portion of the coil are disposed generally within the first bulkhead and the turns of the second portion of the coil are disposed generally outside the first bulkhead; The first partition has a slit through which the coil passes. High temperature superconductor (HTS) magnets.

2. 2. The magnet of claim 1, wherein the housing comprises a first structural plate and a second structural plate, the coil is disposed between the first structural plate and the second structural plate, and the first bulkhead comprises a wall extending between the first structural plate and the second structural plate.

3. The magnet of claim 2 , wherein said first structural plate includes a first circular slot, and said first bulkhead is disposed within said first circular slot.

4. 4. The magnet of claim 3, wherein said first bulkhead is removably inserted within said first circular slot, and said first bulkhead is freely rotatable within said first circular slot.

5. The magnet according to claim 1 , wherein the slit extends to a height of the first partition wall.

6. 2. The magnet of claim 1, wherein an outer shape of the first partition is a helical shape, and the slits in the first partition are gaps between adjacent turns of the helical shape of the first partition.

7. The magnet of claim 1 , wherein the HTS material is an HTS tape.

8. The magnet of claim 7 further comprising a conductive material disposed between at least some of the turns of the coil.

9. 9. The magnet of claim 8, wherein the coil is formed from multiple layers of HTS tape wound into multiple turns and the layer of conductive material.

10. 8. The magnet of claim 7, wherein the coil includes turns of the HTS tape arranged such that turns of the HTS tape contact faces of the HTS tape in adjacent turns.

11. 10. The magnet of claim 1, further comprising a first conductive ring coupled to an inner end of the coil and a second conductive ring coupled to an outer end of the coil.

12. 2. The magnet of claim 1, wherein the housing includes a second partition disposed outside the first partition and having a slit through which the coil extends, and wherein the turns of the first portion of the coil and at least some of the turns of the second portion of the coil are disposed entirely within the second partition of the coil.

13. The magnet of claim 1 , wherein each of the housing and the first bulkhead comprises steel, an austenitic nickel-chromium alloy, and / or a nitrogen-strengthened austenitic stainless steel.

14. A magnet assembly comprising a plurality of instances of the magnet of claim 1.

15. a plurality of pancakes, each of the pancakes having one or more turns of high temperature superconductor (HTS) tape that generates a magnetic field when an electric current is applied to the pancake, each of the pancakes further having one or more joints for electrically coupling the one or more turns of the HTS tape as part of an electric circuit; a plurality of cooling plates, each of the cooling plates having a terminal for thermally coupling the cooling plate to a cooling device; A magnet assembly comprising: a magnet assembly, wherein the plurality of pancakes and the plurality of cold plates are stacked in an alternating fashion, each of the pancakes being electrically coupled by its one or more joints to the joints of either one or two nearby pancakes, thereby forming an operating current path including the HTS tape in each of the pancakes, and each of the pancakes being adjacent to either one or two of the cold plates for removing heat from the pancake by thermal conduction to the cooling device.

16. 16. The magnet assembly of claim 15, wherein each of the pancakes comprises steel, or an austenitic nickel-chromium alloy, or a nitrogen-strengthened austenitic stainless steel.

17. The magnet assembly of claim 15 , wherein the HTS tape of at least one of the pancakes comprises rare earth copper oxide.

18. The magnet assembly of claim 15 , wherein the one or more bonding bodies of at least one of the pancakes comprises copper.

19. 16. The magnet assembly of claim 15, wherein the one or more abutments of each of the pancakes are located on at least a portion of an inner diameter of the pancake, or a portion of its outer diameter, or a portion of both the inner diameter and the outer diameter.

20. 16. The magnet assembly of claim 15, wherein a first one of the pancakes comprises a first face having a joint on an outer diameter thereof and a second parallel face having a joint on an inner diameter thereof.

21. 21. The magnet assembly of claim 20, wherein the first one of the pancakes is electrically coupled to a mating body on the outer diameter of a second one of the pancakes by the mating body on its outer diameter, and the first one of the pancakes is electrically coupled to a mating body on the inner diameter of a third one of the pancakes by the mating body on its inner diameter.

22. 16. The magnet assembly of claim 15, wherein each pancake at the top of the stack and each pancake at the bottom of the stack has an inner surface with a joint on either its outer diameter or its inner diameter that is electrically coupled to the joint of the other pancake, and parallel outer surfaces that have no joint.

23. 16. The magnet assembly of claim 15, wherein at least one of the pancakes comprises a plurality of channels separated by one or more removable bulkheads for withstanding radial loads, each channel having one or more turns of the HTS tape, each removable bulkhead having a feed-through connecting the turns of the HTS tape in nearby channels.

24. 24. The magnet assembly of claim 23, wherein the HTS tape of the at least one of the pancakes is soldered to at least one of the plurality of channels, or soldered to the one or more bonding bodies, or both.

25. 24. The magnet assembly of claim 23, wherein the one or more turns of HTS tape in each of the channels approximately fills a volume of the channel.

26. 16. The magnet assembly of claim 15, further comprising a conductive gasket between the joints of each of two adjacent stacked pancakes.

27. 16. The magnet assembly of claim 15, further comprising a thermally conductive foil, or grease, or wire mesh between one of the pancakes and an adjacent stacked cold plate.

28. The magnet assembly of claim 15 , wherein the plurality of pancakes and the plurality of cold plates are connected by bolts at both the inner diameter and the outer diameter of the stack.

29. 16. The magnet assembly of claim 15, further comprising additional structural plates at the top and bottom of said plates stacked and bolted together, said stacked plates being pressed together by said additional structural plates.

30. 16. The magnet assembly of claim 15, wherein the HTS tape in at least one of the pancakes is co-wound with copper, steel, or both copper and steel.

31. The magnet assembly of claim 15 , wherein at least two of the pancakes have different sizes or shapes.

32. 16. A magnet assembly as claimed in claim 15, wherein said cooling device comprises a cryo-cooler, or cryo-refrigerator, or heat exchanger utilising a continuous flow of cryogenic liquid and / or gas.

33. The magnet assembly of claim 15 further comprising a thermal radiation shield.

34. The magnet assembly of claim 33 , wherein the thermal radiation shield comprises copper and / or aluminum.

35. 35. The magnet assembly of claim 34, wherein the copper is cut to limit eddy currents and to limit Lorentz forces during magnet quench.

36. The magnet assembly of claim 33 wherein said thermal radiation shield is encased in multiple layers of insulation.

37. 37. The magnet assembly of claim 36, wherein said multi-layer insulation includes alternating layers of spacer material and a substrate having an aluminum coating deposited thereon having a barrier.

38. 1. A magnet assembly comprising a plurality of pancakes, each of said pancakes comprising: Housing and a plurality of turns of high temperature superconductor (HTS) tape disposed within the housing; one or more conductive joints coupled to the HTS tape and disposed on the exterior of the housing; a plurality of cooling plates, each of the cooling plates having a terminal for thermally coupling the cooling plate to a cooling device; a magnet assembly, wherein the plurality of pancakes and the plurality of cold plates are alternately arranged in a stack, each of the pancakes in the stack being electrically coupled by its one or more conductive joints to the joints of either one or two nearby pancakes in the stack, thereby forming an operating current path through the stack including the HTS tape in each of the pancakes, and each of the pancakes being adjacent and thermally coupled to either one or two of the cold plates.

39. A housing for holding a wound tape for generating a magnetic field, said housing comprising: a first structural plate having one or more first circular slots; one or more bulkheads, each bulkhead having a feedthrough connection for winding the tape from an inner diameter of the bulkhead to an outer diameter of the bulkhead, each bulkhead removably and rotatably inserted into a corresponding one of the first circular slots; a second structural plate having one or more second slots, each bulkhead being removably inserted into a corresponding one of the second slots; and A housing comprising:

40. 40. The housing of claim 39, wherein one of the partitions includes a through-connection slit that does not extend the entire height of the partition.

41. 40. The housing of claim 39, wherein one of the partitions includes a through-connection slit that extends the entire height of the partition.

42. 40. The housing of claim 39, wherein one of the partitions comprises a spiral having a radially uniform thickness.

43. 40. The housing of claim 39, wherein each bulkhead has a feedthrough for holding a wound tape for generating a magnetic field, the wound tape being co-wound with copper, or steel, or both copper and steel.

44. 1. A method of winding conductive tape to form a magnet, the method comprising: (a) providing a first structural plate having a surface with one or more circular slots and having a first electrical bond on an inner diameter thereof; (b) physically and electrically coupling the conductive tape to the first electrical contact; (c) wrapping the conductive tape in a circular shape on the surface of the first structural plate until the conductive tape reaches one of the circular slots; (d) a slot for inserting a partition wall having a through-connection into said one of said circular slots in a removable manner; wherein the bulkhead is rotated within the one of the circular slots so that its feedthrough aligns with the azimuthal position of the wrapped conductive tape; (e) wrapping the conductive tape on the surface of the first structural plate, through the feedthrough, and around an outer diameter of the septum, thereby minimizing a gap between the conductive tape and the septum; The method includes:

45. 45. The method of claim 44, further comprising repeating steps (c) through (e) for each additional slot of the one or more circular slots.

46. 45. The method of claim 44, wherein the first structural board has a second electrical joint at an outer diameter thereof, the method further comprising the step of physically and electrically coupling the conductive tape to the second electrical joint.

47. 45. The method of claim 44, further comprising adding a layer of indium adjacent to the wrapped conductive tape.

48. providing a second structural plate having a surface with a second circular slot; positioning the second structural plate flush with the wrapped conductive tape such that the bulkhead is removably inserted into the second circular slot; 45. The method of claim 44, further comprising:

49. 45. The method of claim 44, wherein the conductive tape is co-wound with copper, steel, or both copper and steel.

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