Current pulse quench heating method for non-insulated superconducting magnets

Abstract

Provided herein are systems and methods for inducing a quench in a non-insulated superconducting magnet. Certain techniques described herein operate the non-insulated superconducting magnet by applying a first current to the non-insulated superconducting magnet and induce a quench in the non-insulated superconducting magnet at least in part by applying a second current to the non-insulated superconducting magnet, the second current being opposite in direction to the first current.

Description

[Technical Field]

[0001] Cross-reference to related applications This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application No. 62 / 482,382, filed January 31, 2023, which is incorporated herein by reference in its entirety. Field This application relates to non-insulated superconducting magnets, and more particularly to systems and methods for inducing quenches in non-insulated superconducting magnets. [Background technology]

[0002] A superconductor is a material that has no resistance to electrical current (is superconducting) below a certain critical temperature. For many superconductors, operation of these materials in the superconducting state below the critical temperature requires intense cooling, such as with liquid or supercritical helium.

[0003] High-temperature superconducting (HTS) magnets can experience quenches, which are transitions of the magnet's superconductor from a superconducting to a non-superconducting state. Summary of the Invention

[0004] An embodiment relates to a method of inducing a quench in a non-insulated superconducting magnet, the method including operating the non-insulated superconducting magnet by applying a first current to the non-insulated superconducting magnet, and inducing a quench in the non-insulated superconducting magnet at least in part by applying a second current to the non-insulated superconducting magnet, the second current being in an opposite direction to the first current.

[0005] One embodiment relates to a system for inducing a quench in a non-insulated superconducting magnet, the system including the non-insulated superconducting magnet and a controller configured to operate the non-insulated superconducting magnet by applying a first current to the magnet and to induce a quench in the magnet at least in part by applying a second current to the magnet, the second current being in an opposite direction to the first current.

[0006] One embodiment relates to a superconducting, non-insulated magnet comprising: a plate; a plurality of turns of superconducting material within grooves in the plate, the plurality of turns extending from a first terminal having a first electrical connection extending outside the plate to a second terminal having a second electrical connection extending outside the plate; a first extension including a first partial turn of superconducting material extending beyond the first terminal; and a second extension including a second partial turn of superconducting material extending beyond the second terminal.

[0007] Some embodiments relate to a system comprising a superconducting, non-insulated magnet as described herein and a controller configured to operate the superconducting, non-insulated magnet by applying a first current to the superconducting, non-insulated magnet. [Brief explanation of the drawings]

[0008] Various aspects and embodiments are described with reference to the following figures, which should be appreciated, are not necessarily drawn to scale. For clarity, not every component is labeled in every drawing. In the drawings: [Figure 1-1] 1 illustrates example magnet components capable of implementing quench heating techniques in accordance with certain embodiments described herein. [Figure 1-2] 1 illustrates example magnet components capable of implementing quench heating techniques in accordance with certain embodiments described herein. [Figure 1-3]1 illustrates example magnet components capable of implementing quench heating techniques in accordance with certain embodiments described herein. [Figure 2A] 2 illustrates a top view of the in-wind plate of the example magnet of FIG. 1 in accordance with an embodiment of the technology described herein. [Figure 2B] 2B illustrates a bottom view of the example winding introduction plate of FIG. 2A in accordance with an embodiment of the techniques described herein. [Figure 2C] 2 illustrates a top view of an out-wind plate of the example magnet of FIG. 1, according to an embodiment. [Figure 2D] 2D illustrates a bottom view of the example winding lead-out plate of FIG. 2C in accordance with an embodiment of the techniques described herein. [Figure 2E] 2 illustrates an example terminal plate for the example magnet of FIG. 1 in accordance with certain embodiments of the technology described herein. [Figure 2F] 2F illustrates a bottom view of the example terminal plate of FIG. 2E in accordance with an embodiment of the technology described herein. [Figure 2G] 1 shows a cross-sectional view of a magnet stack according to an embodiment of the technology described herein. [Figure 3] 2 illustrates an example pair of plates for the example magnet of FIG. 1 in accordance with certain embodiments of the technology described herein. [Figure 4] 1 illustrates an example method for inducing a quench in an uninsulated magnet, according to certain embodiments of the techniques described herein. [Figure 5] 5 shows an example plot depicting the current applied to the magnet over time during the example method of FIG. 4, according to certain embodiments of the techniques described herein. [Figure 6] 5 shows an example plot depicting the temperature generated by a magnet over time during the example method of FIG. 4, according to certain embodiments of the techniques described herein. [Figure 7] 1 is an example diagram illustrating the path of current in an uninsulated magnet during application of a first current to the uninsulated magnet in accordance with an embodiment of the technology described herein. [Figure 8] FIG. 1 is an example diagram illustrating current paths within an uninsulated magnet during an open circuit period in accordance with certain embodiments of the technology described herein. [Figure 9] FIG. 1 is an example diagram illustrating the paths of current components driven within an uninsulated magnet by application of high-speed pulsed current to terminals in accordance with certain embodiments of the technology described herein. [Figure 10] 10A-10H illustrate alternative conductor and junction arrangements for facilitating quench heating functionality in accordance with certain embodiments of the techniques described herein. [Figure 11] 11A-11H illustrate alternative arrangements for partial quench heating functionality according to certain embodiments of the techniques described herein. [Figure 12A] FIG. 12A shows an example of a control circuit including an uninsulated magnet, according to an embodiment of the technology described herein. [Figure 12B] FIG. 12B shows an example of a control circuit including an uninsulated magnet, according to an embodiment of the techniques described herein. [Figure 12C] FIG. 12C shows an example of a control circuit including an uninsulated magnet, according to an embodiment of the techniques described herein. DETAILED DESCRIPTION OF THE INVENTION

[0009] An electromagnet ("magnet") can have multiple circuits, with a conductor arranged around an axis. Conventional magnets have an insulated conductor, with electrically insulating material placed around the conductor to prevent current from forming a path outside the conductor. Electromagnets made of superconductors have zero resistance when in a superconducting state.

[0010] A non-insulated (NI) magnet is a superconducting electromagnet that has at least a partially conductive path between adjacent circumferential circuits of the superconductor. When the conductor is superconducting, there is zero resistance and voltage difference between the circumferential circuits during steady-state operation, and all current flows through the superconductor. As used herein, the term "NI" is intended to apply to both magnets traditionally referred to as NI magnets and magnets traditionally referred to as partially insulated (PI) magnets, since the techniques and structures described herein apply to both types of magnets.

[0011] Certain NI magnets are exceptionally strong mechanically and can exhibit exceptional stability against the formation of non-superconducting zones that lead to quenching. A quench is the transition of a magnet's superconductor from a superconducting to a non-superconducting state. Robust NI magnets may contain one or more plates made of steel or other metals, with the superconductor disposed within grooves in the plate(s). However, under certain circumstances, even more robust magnets may become thermally unstable and quench. A region of superconducting material transitions from a superconducting to a non-superconducting state when the conditions for maintaining superconductivity are no longer met, for example, when the temperature exceeds a critical temperature. The critical temperature naturally depends on various parameters. For high-temperature superconductors (HTS), the critical temperature is higher than for low-temperature superconductors (LTS). HTS material or HTS superconductor, as used herein, refers to a superconducting material that has a critical temperature greater than 30K in the absence of a self-field.

[0012] In superconducting magnets, when a coil is no longer superconducting, resistance in the magnet increases. When current passes through an area of ​​increased resistance, heat is generated. Uncontrolled and unwanted heat generation can lead to damage to the magnet. Damage can occur if the magnetic energy is concentrated in a small spatial region and / or if the Lorentz load exceeds the allowable value due to large currents. When there are many coils, structural damage can occur due to unbalanced loads if some coils quench earlier than others.

[0013] The inventors have recognized that a technique for controlling quenching would be advantageous. In some cases, a magnet may need to be quickly disabled (shut down), which requires an intentional quench. It is desirable to stop the magnet by intentionally quenching it without incurring damage. It is desirable to induce quenching uniformly and quickly without causing damage to the magnet. Damage to the magnet not only costs money and potentially requires replacement of magnet parts, but can also result in unwanted downtime of associated equipment that uses the magnet, such as an MRI machine or a tokamak reactor.

[0014] Accordingly, systems and techniques are described herein for intentionally and quickly inducing a quench in a non-insulated magnet. The techniques described herein can be used to uniformly and quickly disable, or "turn off," a magnet before damage to the magnet occurs. The inventors have recognized that aspects of the magnet itself can be exploited to induce a quench. For example, current may be rapidly changed in the magnet's terminals to cause heating. While it is typically desirable to slowly charge a superconducting magnet to avoid a quench, rapid changes in current to the magnet can make it easier to intentionally induce a quench. The radial current flow of a non-insulated magnet can be utilized to provide quench heating, as described herein. The magnet and / or the method of operating the magnet may be modified to increase the efficiency (e.g., speed) and uniformity of the quench.

[0015] Figure 1 shows example components of a magnet in which quench heating techniques can be implemented according to certain embodiments described herein. Figure 1 shows the arrangement of conductor paths and joints on alternating plates 102 that form a "pancake" shaped magnet. In the illustrated embodiment, the magnet is a grooved, plated, non-insulated high temperature superconducting (HI-HTS) wire-wound magnet.

[0016] In the illustrated embodiment, the magnet is a stacked plate magnet comprising multiple plates 102. One or more of the plates may be electrically conductive. In the illustrated embodiment, the magnet comprises multiple plates, but in some embodiments, the magnet may comprise a single plate. Additionally, in the illustrated embodiment, the magnet comprises plates having conductors disposed on their top surfaces in the form of multiple circumferential circuits, although other magnet configurations are possible.

[0017] Referring to panel 3 of Figures 1 and 3, the magnet plate 102 can include a groove 104 formed on the surface of the plate 102 and a conductor 106 disposed within the groove 104. The conductor 106 can be composed of a high-temperature superconductor (HTS), such as an HTS tape stack, as shown in the illustrated embodiment. The HTS tape stack can include multiple HTS tapes stacked on top of each other along their width and length. The HTS tape stack can thereby have a thickness equal to (or approximately equal to) the thickness of an individual tape multiplied by the number of tapes in the stack. In some embodiments, the conductor 106 can be a composite of HTS, co-wind tape, copper caps, and solder. The conductor 106 and groove 104 can form multiple circumferential circuits 110, each spanning 360 degrees about an axis extending substantially perpendicular to the plane of the plate 102. The conductors 106 disposed on the plate 102 and the grooves 104 may include any suitable number of circumferential circuits (e.g., at least two circumferential circuits, at least three circumferential circuits, at least four circumferential circuits, at least five circumferential circuits, at least six circumferential circuits, at least seven circumferential circuits, at least eight circumferential circuits, or any other suitable number of circumferential circuits). In one embodiment, the plurality of circumferential circuits 110 may form a spiral-shaped pattern.

[0018] Conductive paths can enter and / or exit the exterior of a plate to the exterior of that plate. The conductive paths are formed by conductors 106 and bond pads 108 disposed on plate 102, which form a conductive connection between a conductor disposed on a first plate and a second conductor formed on a second plate. The bond pads 108 may each comprise a junction formed of a conductive material. In some embodiments, the junctions may be non-superconducting. In some embodiments, the junctions may be formed of a material such as copper. The conductive paths extend to and / or from a subsequent plate and can be formed by the conductor(s) and / or bond pad(s) of the subsequent plate. In some embodiments, the conductive paths can enter and / or exit from / below a plate. In some embodiments, the conductive paths can enter and / or exit from / above a plate. In some embodiments, the conductive paths may enter and / or exit the plate from the sides. As shown in Figures 1-3 and described herein, the magnet may include bond pads 108 located on the plate at the locations where the conductive paths enter or exit the plate.

[0019] As shown in the embodiment illustrated in FIG. 1 , the magnet may comprise a stacked magnet comprising multiple structures including plates 102, referred to herein as a “pancake.” For each plate, one or more conductors may be disposed on each plate in multiple circuit loops. The conductors of each plate may be conductively connected to form conductive paths between the plates via junctions disposed on bond pads, as described herein. In some embodiments, the multiple circuit loops may extend in a clockwise direction from the inlet junction to the outlet junction. In some embodiments, the multiple circuit loops may extend in a counterclockwise direction from the inlet junction to the outlet junction.

[0020] A stacked magnet configuration can also include a bottom plate. For example, plate 102 shown in panel 1 of FIG. 1 can include a bottom plate. The bottom plate can be placed below the other plates of the magnet and form a substrate for the magnet. Bottom plate 102 can include bond pads 108, and conductive traces can enter the magnet at conductive trace inlets 114. In some embodiments, the bottom plate can include neither grooves nor circumferential lines (e.g., the embodiment shown in panel 1 of FIG. 1). In other embodiments, the magnet base can comprise a bottom plate with conductors disposed in grooves, and the conductors can be formed into multiple circumferential lines (e.g., plate 102 shown in panel 3 of FIG. 1).

[0021] A magnet in a stacked magnet configuration can include multiple plates stacked on top of one another. In embodiments described herein that include a bottom plate, the multiple plates can be positioned above the bottom plate. In embodiments that include a top plate, as described herein, the multiple plates can be positioned below the top plate. Each of the multiple plates 102 can include a respective groove 104 formed within a respective plurality of circumferential circuits 110. For each plate 102, a conductor 106 can be positioned within the groove 104 of the plate 102 to form the respective plurality of circumferential circuits 110 of the plate 102. As described herein, the conductor 106 can also comprise an HTS tape stack. Each plate 102 can include a respective HTS tape stack. In some embodiments, the conductor can include one conductor winding through each of the magnet's multiple plates.

[0022] Specifically, in the embodiment illustrated in Figures 1 and 3, the magnet comprises alternating plates. Each of the alternating plates can be either a "winding lead-in" plate 102A or a "winding lead-out" plate 102B. Whether a plate is a winding lead-in plate or a winding lead-out plate depends on where the electrical conduction path enters and exits the plate, as described herein. The electrical conduction path can enter each plate from a lower plate located below the current plate in the stack configuration and exit from this plate to an upper plate located above the current plate in the stack configuration (e.g., via joints and bond pads as described herein).

[0023] For example, panels 3 and 7 in FIG. 1 show panels with "winding lead-in" plates. FIG. 2A shows the top surface of "winding lead-in" plate 102A. In winding lead-in plate 102A, conductors 106 from the lower plate join the plate at a first (entrance) junction at winding lead-out bond pad 108A on the outer periphery of the plate. Conductors 106 wind clockwise into multiple circumferential circuits 110 (e.g., a spiral configuration) in the plane of the plate, and conductors 106 exit the plate toward the upper plate at a second (exit) junction at winding lead-in bond pad 108B on the inner periphery of the plate. Panels 5 and 9 in FIG. 1 show panels with "winding lead-out" plates. FIG. 2C shows the top surface of "winding lead-out" plate 102B. In the winding exit plate, conductor 106 from the lower plate is bonded to winding exit plate 102B at a first (entrance) interface at winding entry bond pad 108B on the inner periphery of the plate. Conductor 106 winds in a clockwise direction into multiple circumferential circuits 110 (e.g., a spiral configuration) in the plane of the plate, and conductor 106 exits the plate to the upper plate at a second (exit) interface at winding exit bond pad 108A on the outer periphery of the plate.

[0024] The magnet may include any suitable number of plates, and although the embodiment depicted in Figure 1 shows panels 1-9 and 18-20 for illustrative purposes, it should be understood that additional plates may be inserted or fewer plates may be used than the number shown in the embodiment depicted in Figure 1.

[0025] The stacked magnet configuration may also include a top plate, as shown in panel 19 of FIG. 1 and in FIGS. 2E-2F. FIG. 2E shows the top surface of the magnet's top plate. FIG. 2F shows the bottom surface of the magnet's top plate. The top plate may be positioned above the other plates of the magnet. The top plate may include bond pads 108, and conductors 106 exit the magnet at conductive path exit 115. The top plate may not include grooves or circumferential lines in some embodiments, as in the illustrated embodiment of panel 20 of FIG. 1. In other embodiments, the top plate may be a plate with conductors disposed in grooves in the plate and arranged in multiple circumferential lines (e.g., either a winding in-plate or a winding out-plate as described herein). Insulation may be added between the plates of the magnet, as described herein. The bottom surface of the top plate includes insulation 112, as shown in FIG. 2F.

[0026] In some embodiments, an electrically insulating material (“insulator”) may be inserted between one or more (e.g., each) of the plates of a magnet. As shown in FIGS. 2B, 2D, 2F, and 1, in panels 2, 4, 6, 8, 18, and 20, in the illustrated embodiment, an insulator 112 is inserted between each plate of the magnet. In some embodiments, the insulator 112 may include a cutout 109. The cutout 109 may also serve to expose a portion of an adjacent plate. For example, as shown in FIG. 1, the insulator 112 between plates 102 includes a cutout 109 that exposes the bond pads 108 of the plates 102, allowing the conductors 106 of each plate 102 to form a conductive connection with the conductors 106 of the adjacent plate 102 via the bond pads 108.

[0027] Referring to FIG. 2G, a cross-sectional view of a stack of magnet structures 250 is shown. Specifically, this magnet structure may comprise the HTS pancakes of the example magnets described herein. Each pancake 252 may include a base plate 254, which is typically formed of a conductive material such as steel. The base plate 254 may have a groove 256 (or a series of grooves) through which an HTS material 258 (e.g., HTS tape) is wound. The HTS material 258 may form a superconducting path capable of carrying an electric current to form a magnetic field. In an embodiment, the HTS material 258 comprises a stack of HTS tapes. In an embodiment, the pancakes may have a shape corresponding to the toroidal shape of a tokamak for use as a toroidal field (TF) coil.

[0028] As described herein, the inventors have developed techniques for rapidly inducing quenches in uninsulated magnets. For example, the techniques described herein can facilitate inducing quenches in magnets in a controlled manner to avoid damage that could otherwise be caused by uncontrolled quenches.

[0029] A technique for inducing a quench in such a non-insulated superconducting magnet can begin by operating the non-insulated superconducting magnet by applying a first current to the non-insulated superconducting magnet. For example, the first current can be applied to the terminals of the magnet so that the first current flows through multiple circumferential circuits of the magnet. In a stacked plate magnet having multiple plates, the first current can flow through the multiple plates of the magnet (through the conductive path formed by the magnet's conductor(s) and bond pad(s)).

[0030] In some embodiments, the first current may increase and / or decrease over time. For example, the current may be a ramped current that increases over time (e.g., during a period of charging the magnet). In some embodiments, operating a non-insulated superconducting magnet may include operating the magnet in a "steady state" state by applying a substantially constant operating current to the terminals of the magnet.

[0031] A quench can be induced in a magnet, at least in part, by applying a second current to a non-insulated superconducting magnet after applying a first current to the magnet. For example, a second current can be applied to the terminals of the magnet such that the second current flows through multiple circumferential circuits of the magnet. In a stacked plate magnet having multiple plates, the second current can flow (through conductors) through the multiple plates of the magnet. Application of the second current can cause the magnet to quench, as described further herein.

[0032] The second current may be opposite in direction to the first current. For example, the applied first current may be a positive current flowing in one direction (e.g., clockwise with reference to the circuit diagram of FIG. 12A described herein), and the second current may be a reverse current pulse flowing in the opposite direction to the positive current (e.g., counterclockwise with reference to the circuit diagram of FIG. 12A). In some embodiments, the second current may be greater in magnitude than the first current (e.g., two times greater, three times greater, four times greater, etc.).

[0033] The quench inducing methods described herein, along with additional acts, are incorporated into an example method 400 shown in Figure 4. As shown in Figure 4, method 400 begins in act 402 with operating a magnet (e.g., an uninsulated high temperature superconducting magnet) by applying a first current to the terminals of the magnet. For example, the first current may be as previously described herein.

[0034] During normal magnet operation (e.g., during act 402), a first current flows into the plate (e.g., conductor) through the inlet junction. As described herein, in some embodiments, the first current may comprise a steady-state current (e.g., a substantially constant current), or the first current may comprise a variable current (e.g., a ramped current during charging of the magnet, etc.). In a stacked plate magnet, the current may enter the plate through a terminal plate, as shown, for example, in panel 20 of FIG. 1. As can be seen with reference to FIG. 7, for example, the current enters the lowermost winding lead-in pancake, on the winding lead-out junction of winding lead-out bond pad 108A. The current circulates clockwise within this plate 102, passing through the multiple circuit circuits 110 of the conductor 106, until it reaches winding lead-out bond pad 108B. The direction of the arrows in FIG. 7 indicates the direction of the current in the magnet during act 402. The current passes through the winding inlet plate 102A, through the winding inlet joint, and into the winding outlet plate located above the winding inlet plate.

[0035] The current exits the winding introduction plate through the winding introduction bond pad and then enters the winding introduction plate through the winding introduction bond pad, as shown in FIG. 7. The current circulates clockwise in this plate 102B through the multiple circuits 110 of the conductor 106 until it reaches the winding introduction bond pad 108A. The direction of the arrows in FIG. 7 indicates the direction of the current in the magnet during act 402. The current then passes through the winding introduction bond pad 108A and enters the winding introduction plate located above the winding introduction plate 102B. The alternating pattern of winding introduction and winding introduction plates continues to the top terminal plate, where the current exits the winding pack.

[0036] The current path shown in FIG. 7 generates a magnetic field during act 402, resulting in energy storage in the magnet. The generated magnetic field can have very high inductance (e.g., about 11.7 H). There may be low turn-to-turn resistance (e.g., about 20 nanoohms). The L / R time may be very long (e.g., about 45 hours for a magnet consisting of 3600 circuits). The azimuthal current flowing in each circuit may be essentially fixed. However, the magnets described herein are not limited to these parameters.

[0037] Figure 5 shows an example plot 500 representing the current applied to a non-insulated superconducting magnet over time during the example method 400 of Figure 4. Specifically, Figure 5 shows a typical terminal current and average winding waveform for an NI-HTS magnet undergoing a quench, which begins with an open circuit followed by the application of a reverse current pulse.

[0038] 6 shows an example plot 600 illustrating the temperature generated by a magnet over time during the example method of FIG. 4, in accordance with an embodiment of the techniques described herein. During the application of the first current to the magnet in act 402, the temperature of the magnet winding pack (initial T) is relatively low, as shown in FIG. 6. The current (I) applied during act 402, shown as time period A in FIG. op ) may be positive, and in some embodiments, may be approximately fixed, as shown in FIG.

[0039] The method 400 may optionally proceed to act 404, where the magnet is open-circuited. To open-circuit the magnet, any power source supplying current to the magnet's terminals (e.g., the drive electronics shown in FIGS. 12A-12C) may be disconnected. During the open-circuit act, no current flows into or out of the bond pads from the other plate of the magnet. As shown in FIG. 5, the current applied to the magnet during the open-circuit step, designated B in plot 500 of FIG. 5, is zero.

[0040] FIG. 8 is an example diagram illustrating the current paths in a non-insulated magnet during periods when the magnet is open-circuited in accordance with certain embodiments of the technology described herein. The arrows in FIG. 8 indicate the direction of current flow in the magnet's winding lead-in and lead-out plates 102A-102B. The relative sizes of the arrows correspond to the relative strengths of the current at that point. As shown in FIG. 8, the total current flow in the magnet is azimuthal during act 404. A radial component of this current flows across the circumferential circuit 110, opposing the radial component of the current flowing along the helix. In the winding lead-in plates, the azimuthal current flow is outward. In the winding lead-out plates, the azimuthal current flow is inward.

[0041] The radiation current flows across the turn-to-turn resistance of the magnet, as shown in Figure 8. The turn-to-turn resistance can be based on the winding spacing and resistivity of the base plate. The resulting losses in the magnet due to the current flowing across the magnet's circumferential circuit are I 2 R, essentially achieving internal quench heating, which is supplied by the magnet's stored energy. The magnet begins to heat up as a result of the resistance increase initiated by the act of opening the magnet. Plot 600 of Figure 6 shows the temperature rise of the winding pack during the open-circuit act.

[0042] It should be appreciated that the act of open-circuiting the magnet is optional. In some embodiments, the technique for inducing a quench may not include the act of open-circuiting the magnet, as described herein. In other embodiments, the technique may include the act of open-circuiting the magnet. The inventors have recognized that the act of open-circuiting the magnet may cause a temperature rise in the winding pack to occur more quickly, allowing for more efficient quenching of the magnet.

[0043] The inventors recognize that the duration of the opening-circuit act may be varied. The duration of the opening-circuit act may be optimized to reduce the amount of energy required when applying the rapid current pulse in act 406 described herein. For example, a longer duration of the opening-circuit may result in a greater temperature rise in the winding pack, thereby reducing the remaining temperature rise required to achieve quenching during the rapid current pulse act. However, a shorter duration of the opening-circuit act may also result in a more efficient (e.g., faster) quench. Thus, the duration of the opening-circuit act may be optimized based at least on these factors.

[0044] The method 400 may then proceed to Act 406. In Act 406, a second current may be applied to the terminals of the magnet. The second current may comprise a rapid current pulse. As described herein, the second current may comprise a reverse current pulse in a direction opposite to the direction of the first current applied to the magnet in Act 402, as shown in plot 500 of FIG. 5. The application of the second current is shown during time period C in FIG. 5. The second current may flow through the magnet in the same manner as the first current, except that its direction is opposite to the direction of flow of the first current. As shown in plot 600 of FIG. 6, the second current may accelerate heating of the magnet, at least until the temperature of the winding pack reaches a critical temperature at which quenching occurs.

[0045] In some embodiments, the second current may be approximately equal in magnitude to the first current applied in act 402. Application of a second current pulse having a magnitude approximately equal to the magnitude of the immediately preceding applied operating current achieves the quench heating function described herein. A reverse current pulse having a magnitude approximately equal to the operating current can increase heating of the magnet by a factor of four compared to an act that opens the magnet. The inventors have determined that a reverse current pulse having a magnitude approximately equal to the operating current can be applied without any modification to the HTS of the magnet receiving the operating current.

[0046] In some embodiments, the second current may have a magnitude that is different from the magnitude of the first current. For example, in some embodiments, the second current may be greater in magnitude than the first current (e.g., two times greater, three times greater, four times greater, etc.). FIG. 5 shows the first current (I op 1 shows an example of the relative magnitudes of the first current (IRCP) and the second current (IRCP).

[0047] As described herein, the duration of applying the open circuit and / or the duration of applying the second current can be optimized to balance the magnitude of the second current required to perform the quench heating function. For example, a longer open circuit generates more heat during the open circuit step, and therefore less heat is generated during the second current application step. Thus, the duration and magnitude of acts 404-406 can be adjusted as desired (e.g., to perform the quench for a limited amount of time). For example, in one embodiment, the magnitude of the second current is approximately 31 kA. The duration of application of the second current is in the order of seconds (e.g., less than 10 seconds, less than 5 seconds, between 1 and 5 seconds, etc.).

[0048] In some embodiments, the application of the open circuit and the duration of the second current application step can be based on the current density in the copper co-conductor for nominal operating conditions. The intrinsic temperature rise rate in the conductor can be a function of the current density. For the operator to control the quench (i.e., the temperature rise rate), the quench must be induced faster than the intrinsic temperature rise value in the conductor, for example, by application of the quench heating techniques described herein. Otherwise, the magnet controls how the quench proceeds via the quench heating technique instead of the operator.

[0049] 9 is an example diagram illustrating the paths of current components driven in an uninsulated magnet by application of a rapid pulse of current to the terminals, in accordance with certain embodiments of the techniques described herein. Specifically, FIG. 9 shows the current pattern driven by the reverse current pulse. The current entering each plate 102A-102B flows in the reverse azimuthal direction along the winding lead-in and winding lead-out circumferential circuits, as indicated by the arrows in FIG. 9.

[0050] As a result of the rapid current pulse applied in act 406, a portion of the current flowing across the magnet is radial. For the winding lead-in plate 102A, the current flows radially outward across the plate from circumferential circuit to circumferential circuit, as shown by the arrows in FIG. 9. For the winding lead-out plate 102B, the current flows radially inward across the plate from circumferential circuit to circumferential circuit, as shown by the arrows in FIG. 9. Similar to the radial current caused by an open circuit, the current flowing across the magnet's circumferential circuits 110 generates heat due to the increasing resistance of the magnet with each circumferential circuit. As explained herein, the increased resistance can be based on the winding spacing and resistivity of the base plate. The resulting losses in the magnet due to the current flowing across the magnet's circumferential circuits 110 are calculated as I 2 R. As an example, when a rapid current pulse is a reverse current pulse equal to the steady-state current, the radiation current doubles and becomes I 2 R losses increase by a factor of four. In general, the overall I 2 The dissipation of R is (IRCP+I op ) 2 and is limited only by the carrying capacity of the current leads and the winding in and out circuits of the magnet plates.

[0051] The azimuthal current flow in winding lead-in plate 102A is opposite to the azimuthal current flow in winding lead-out plate 102B. In a laminated plate magnet, the magnetic flux generated by these azimuthal current paths cancels significantly due to their opposite directions, reducing their inductance. This reduced inductance allows the current pattern shown in Figure 9 to quickly establish, resulting in azimuthal uniform radial current flow across the plates in the shortest possible time.

[0052] In embodiments that include performing an open-circuit act prior to applying the second current, the net current in the magnet is a superposition of the patterns in Figures 8-9. The superposition of the currents caused by acts 404-406 (shown in Figures 8-9) results in cancellation of the steady-state azimuthal currents flowing through the junctions of the bond pads 108 of the plates 102A-102B.

[0053] In act 408, quenching is initiated. Specifically, when a critical temperature is reached, the magnet transfers its azimuthal current to the copper components of the conductor (e.g., copper co-wind and cap). In doing so, the magnet can transform into a "copper" magnet, decaying with its characteristic L / R time and inducing a quench by converting its stored energy into thermal energy in the magnet.

[0054] The quench induction techniques described herein can be performed in response to any suitable trigger. The quench induction techniques described herein can, in some embodiments, be initiated in response to a command from an operator. For example, the operator may decide to perform a controlled magnet quench and then issue a command to initiate the quench induction technique. In some embodiments, the quench induction technique can be initiated in response to a temperature change in the magnet. For example, it may be desirable to intentionally induce a controlled magnet quench in response to a temperature increase in the magnet. In some embodiments, the intentional quench induction technique can also be performed in response to a prediction of a temperature change (e.g., a temperature increase). For example, given the current state of the system, a processor may execute a model that predicts a temperature increase. When a temperature increase is predicted, the system can execute a technique to intentionally induce a magnet quench.

[0055] It should be understood that additions and / or alternatives to the quench induction techniques described herein are possible. For example, the techniques described herein can be modified with one or more additions and / or alternatives that can improve quenching (e.g., quench uniformity and / or rate). Examples of additions and alternatives are described further herein.

[0056] In some embodiments, a superconducting, uninsulated magnet can be constructed with one or more extensions, each including a partial circuit of superconducting material that extends beyond the magnet's terminals. The extensions may also be referred to herein as conductor extensions. As described herein, the magnet can include a plate having grooves forming multiple circuit patterns and conductors (e.g., comprising superconducting material such as HTS tape stacks) arranged in the grooves in multiple circuit patterns. The conductors can enter and exit the plate at junctions, also referred to herein as terminals. As shown in FIG. 3 , in the winding entry plate 102A, multiple circuit patterns 110 can extend in a direction (clockwise in the illustrated embodiment) from an entry junction on the winding exit bond pad 108A to an exit junction on the winding entry bond pad 108B. A first extension 116A, including a partial circuit of conductor, extends beyond the entry junction on the winding exit bond pad 108A. For example, the first extension 116A can extend in the opposite direction from the plurality of circumferential circuits beyond the entry junction on the winding lead-out bond pad 108A to the exit junction on the winding lead-in bond pad 108b. The second extension 116B, which includes a partial circumferential circuit of the conductor, extends beyond the exit junction on the winding lead-in plate 108B. The second extension 116B can extend in the opposite direction from the exit junction on the winding lead-in bond pad 108B to the entry junction on the winding lead-out bond pad 108A.

[0057] The inventors have determined that providing one or more extensions to a magnet facilitates quickly driving large radiation currents across the winding pack by an external power source during intentional quenching of the magnet. The extensions provide a low inductance path for the current to promote rapid quench initiation. The extensions can also promote current distribution around the magnet to aid in obtaining more quench uniformity.

[0058] The flow of current in the conductor extension during an intentionally quench-inducing technique will now be described. While a first current (e.g., in one embodiment, a steady-state current) is applied to the magnet and the magnet is open circuited, no current passes through the conductor extension 116. For example, this is shown in Figures 7-8. When a rapid current pulse, such as a reverse current pulse, is applied to the magnet, current passes through the extension. The magnitude of the current in the extension 116 is equivalent to the magnitude of the rapid current pulse applied. For example, this is shown in Figure 9.

[0059] The conductor extension can be designed to handle a particular magnitude of current. For example, in some embodiments, the extension can be designed to handle twice the magnitude of the steady-state operating current. Thus, such a design allows for rapid current pulses equal to twice the steady-state operating current to be used without modifying the other conductors of the magnet. As described herein, during application of the first current (e.g., during steady-state operation), no current flows through the extension. Therefore, given that the extension is not involved in the current path during steady-state operation, the extension can be operated at a critical current level.

[0060] The extensions can also provide a low-inductance current path. The time required for current to pass through the conductor extension can be shorter than the time required for current to pass through multiple circumferential circuits of the conductor. Therefore, initially, current need only exist in the conductor extension. The conductor extensions can be positioned on opposite sides of the upper surface of the plate. The extensions can thus function like a pair of opposing electrodes, inducing current flow between them. Therefore, the resulting current flow in the magnet can be radial (across the circumferential circuits of the conductor).

[0061] The current flowing through the conductor extension may vary along the length of the extension from the value of the rapid current pulse to zero. In one embodiment, tape grading may be employed on the extension to reduce the width of the HTS stacks from a maximum at the junction to near zero at their ends.

[0062] As further described herein, the configuration of the extension may vary. In the illustrated embodiment, the extension comprises approximately one-half the length of one circuit, although other lengths are possible. For example, the extension may comprise approximately one-quarter of a circuit.

[0063] In the illustrated embodiment, the extensions on each plate are equal in length. In other embodiments, the extensions on each plate can have different lengths. Additionally, the extensions on different plates of the magnet can have different lengths.

[0064] In the illustrated embodiment, the bond pads of the magnet plates are diametrically opposed, and therefore the extensions are located on opposite sides of the top surface of the plate. However, in other embodiments, the extensions may be located at different locations other than on opposite sides of the top surface of the plate.

[0065] FIGS. 10A-10H illustrate alternative conductor and junction arrangements to facilitate quench induction in accordance with certain embodiments of the technology described herein. FIGS. 10A-10H illustrate possible embodiments for magnet winding and junction arrangements to which intentional quench induction techniques can be applied. The azimuthal positions of the winding entry and exit junctions are different in the embodiments illustrated in FIGS. 10A-10H. FIG. 10A illustrates the bond pad configuration shown in FIG. 1 and described herein. In the arrangements shown in FIGS. 10B-10D and 10F-10G, the azimuthal positions of the winding entry and exit bond pads are changed compared to embodiments previously described herein (e.g., located in different regions of the plate rather than on the same side of the plate). FIGS. 10A-10D illustrate an embodiment using an extension having a length approximately half that of a full circuit. FIGS. 10E-10H implement a separate C-shaped annular conductor that passes through the plate junctions. The inventors have determined that these C-shaped ring conductors may provide advantages in some cases, such as in designs for very large reverse current pulses. The separate C-shaped ring conductor design may be best suited for tape-on-tape windings and mixed winding schemes.

[0066] In the arrangements of conductors and junctions shown in Figures 10A-10H and 11A-11H, portions are labeled to illustrate how current moves through the conductors. During the application of a short pulse, the portions of the conductors shown in orange (denoted by "0") behave electrically as if they are not involved at all due to the large inductance of these portions. This makes it difficult to change the current in these portions of the conductor. The current in these portions is essentially fixed, despite the fact that the voltage may vary along the winding.

[0067] When a current pulse is driven by applying a voltage to the terminals of the conductor, the cyan portion of the conductor (designated "C") is at a positive potential, while the purple portion of the conductor (designated "P") is at a negative potential. The patterns of the emission current flowing from the cyan portion to the purple portion are shown in Figures 10A-10H and 11A-11H. The conductor configurations shown in Figures 10A-10H result in a uniform emission current flow in the azimuthal direction, while the conductor configurations shown in Figures 11A-11H do not result in a uniform emission current flow in the azimuthal direction.

[0068] 11A-11H illustrate additional variations of the techniques described herein, including components that accommodate partial quench heating. In the embodiments shown in FIGS. 11A-11H, the conductor extensions at the winding entry and exit joints are truncated in the embodiments shown in FIGS. 11A-11D (e.g., one or both of the extensions do not extend fully to the other side of the plate, and one or both of the extensions have a length that is less than half the circumference, e.g., a quarter circumference instead). In the embodiments shown in FIGS. 11A-11D, the truncation at the winding entry joints is different compared to the winding exit joints.

[0069] 11A-11H have efficiency disadvantages compared to arrangements with half-circle extensions, but these embodiments have other advantages. For example, in the embodiment shown in FIG. 11A, the extensions extend only a quarter-circle from the winding entry and exit junctions, thereby reducing the radial width of the base plate in the half section opposite the bond pads.

[0070] The azimuthal distribution of the emission current driven by the rapid (in some embodiments, reverse) current pulse is affected by the length and arrangement of the extended circuit, which can lead to non-uniform heating of the baseplate. In some cases, this can be advantageous to compensate for azimuthal variations in the HTS thermal margin. In some cases, it may be desirable to initiate quenching first in a wide azimuthal zone that includes the bond pads.

[0071] 11E-11H show arrangements of C-shaped annular conductors on winding inlet and outlet junctions similar to the arrangements shown in FIGS. 10E-10H. The quench-inducing techniques described herein can be facilitated by the use of the circuitry of FIGS. 12A-12C. FIGS. 12A-12C illustrate an example control circuit 1200 having an uninsulated magnet, in accordance with an embodiment of the technology described herein. As shown in FIGS. 12A-12C, a power supply (e.g., forming part of drive electronics 1204) supplies a current (sometimes referred to as a "transport current") to the NI magnet. The NI magnet can include a superconducting coil 1206 having electrical terminals for coupling to the power supply. Receiving current from the power supply via the electrical terminals causes the superconducting coil 1206 to generate a magnetic field. FIG. 12A illustrates the example control circuit 1200 during application of a first current (e.g., during a steady state, such as in act 402 of the example method 400). In this state, the drive electronics supplies a first current, which passes through the magnet. For example, as shown in FIG. 12A , in an operating state (e.g., a steady state or charging state) of the NI magnet, switch(es) 1208 controlled by at least one processor 1202 can be closed to allow current to reach the magnet. As described herein, the NI magnet can be open-circuited. FIG. 12B shows an example of control circuit 1200 in the open-circuit state of the circuit (e.g., act 404 of example method 400). To accomplish the open circuit and quickly drop the transport current supplied by the power source to zero, switch(es) 1208 can be opened by providing a control signal to switch(es) 1208 (e.g., using processor 1202) that opens the switch. Current no longer flows from drive electronics 1204. Any current remaining in the magnet flows across the circumferential path of coil 1206, which is devoid of insulation, as shown in FIG. 12B . 12C illustrates an example of control circuit 1200 during application of a second current (e.g., act 406 of the example method 400). In this operation, a second current is applied from drive electronics 1204 in a direction opposite to the flow of the first current. The second current flows across the circumference of coil 1206, which is devoid of insulation, as shown in FIG.

[0072] As used herein, a non-insulated magnet, also referred to herein as a no-insulation magnet, includes a magnet having conductors arranged in multiple circumferential circuits, wherein the electrical resistance between a first circumferential circuit and a second circumferential circuit is less than 1 megaohm (e.g., greater than 0 and less than 1 megaohm, greater than 0 and less than 0.75 megaohms, greater than 0 and less than 0.5 megaohms, greater than 0 and less than 0.25 megaohms, greater than 0 and less than 0.1 megaohms). Additionally, because a non-insulated magnet may have little or no electrical resistance between the circumferential circuits of individual magnet plates, electrical insulators may be located at other locations within the non-insulated magnet in some cases. For example, as described above, electrical insulators may be located between each plate of the magnet. Thus, when referring to a magnet, terms such as "non-insulated," "non-insulated," "NI," and the like refer to low electrical resistance between each circumferential circuit and do not exclude other regions of the magnet from being electrically isolated from each other, in whole or in part.

[0073] An example implementation of the techniques described herein is provided below. (1) A method of inducing a quench in a non-insulated superconducting magnet, the method comprising: operating the non-insulated superconducting magnet by applying a first current to the non-insulated superconducting magnet; and inducing a quench at least partially within the non-insulated superconducting magnet by applying a second current to the non-insulated superconducting magnet, the second current being opposite in direction to the first current. (2) In the method of (1), the magnitude of the second current is greater than the magnitude of the first current. (3) The method of (2), wherein the magnitude of the second current is at least twice the magnitude of the first current. (4) In any one of the methods (1) to (3), the method further includes the step of opening the non-insulated superconducting magnet after applying the first current to the non-insulated superconducting magnet and before applying the second current to the non-insulated superconducting magnet. (5) In any one of the methods (1) to (4), a second current is applied to the non-insulated superconducting magnet so that a radiation current is induced in the non-insulated superconducting magnet. (6) In any one of the methods (1) to (5), the non-insulated superconducting magnet has a plurality of circumferential circuits, and when the first current is applied to the non-insulated superconducting magnet, the resistance between each of the plurality of circumferential circuits is less than 1 megaohm. (7) In any one of the methods (1) to (6), the step of applying the second current to the non-insulated superconducting magnet is performed by a control circuit of the non-insulated superconducting magnet in response to the control circuit receiving a command to disable the non-insulated superconducting magnet or in response to the control circuit making a decision to stop the non-insulated superconducting magnet. (8) In any one of the methods (1) to (7), the non-insulated superconducting magnet includes a high-temperature superconductor. (9) In the method of (8), the non-insulated superconducting magnet comprises a first conductive plate having a first groove and a first high-temperature superconductor (HTS) tape stack including a first plurality of circumferential circuits disposed within the first groove, and when a first current is applied to the non-insulated superconducting magnet, the resistance between each of the first plurality of circumferential circuits of the first HTS tape stack is less than 1 megaohm. (10) In the method of (9), the non-insulated superconducting magnet further comprises a second conductive plate having a second groove and a second HTS tape stack including a second plurality of circumferential circuits disposed within the second groove, and the first HTS tape stack forms a conductive connection with the second HTS tape stack. (11) In the method of (10), the non-insulated superconducting magnet comprises a plurality of conductive plates including a first conductive plate and a second conductive plate, the plurality of conductive plates being arranged in a stacked configuration. (12) In the method of (11), the non-insulated superconducting magnet comprises a conductor including a first HTS tape stack and a second HTS tape stack; a conductor passes from the first conductive plate to the second conductive plate at a first point on the second conductive plate, the first conductive plate being disposed below the second conductive plate in a stacked configuration; the conductor exits the second conductive plate at a second point on the second conductive plate and leads to a third conductive plate in the plurality of conductive plates, the third conductive plate being disposed above the second conductive plate in the stacked configuration; a second plurality of circuit lines of the second conductive plate extending from the first point to the second point; At the first location, the conductor includes a first extension, the first extension extending in a direction opposite to a direction in which the second plurality of circumferential circuits extend from the first location to the second location; At the second point, the conductor includes a second extension, the second extension extending in a direction opposite to the direction in which the second plurality of circumferential circuits extend from the second point to the first point. (13) In the method of (11), the non-insulated superconducting magnet further comprises an electrically insulating material between adjacent plates of the plurality of conductive plates. (14) A system for inducing a quench in a non-insulated superconducting magnet, the system comprising: a non-insulated superconducting magnet; and a controller configured to operate the magnet by applying a first current to the non-insulated superconducting magnet and to induce a quench in the magnet at least in part by applying a second current to the magnet, the second current being opposite in direction to the first current. (15) In the system of (14), the magnitude of the second current is greater than the magnitude of the first current. (16) In the system of (15), the magnitude of the second current is at least twice the magnitude of the first current. (17) In the system of any one of (14) to (16), the controller is further configured to open-circuit the non-insulated superconducting magnet after applying the first current to the non-insulated superconducting magnet and before applying the second current to the non-insulated superconducting magnet. (18) In the system of any one of (14) to (17), the controller is configured to apply a second current to the non-insulated superconducting magnet to induce a radiation current in the non-insulated superconducting magnet. (19) In any one of the systems (14) to (18), the non-insulated superconducting magnet has a plurality of circumferential circuits, and when the first current is applied to the non-insulated superconducting magnet, the resistance between each of the plurality of circumferential circuits is less than 1 megaohm. (20) The system of any one of (14) to (19), further comprising a control circuit configured to apply a second current to the non-insulated superconducting magnet, the control circuit configured to apply the second current to the non-insulated superconducting magnet in response to receiving a command to disable the non-insulated superconducting magnet or in response to making a decision to stop the non-insulated superconducting magnet. (21) In the system of any one of (14) to (20), the non-insulated superconducting magnet includes a high-temperature superconductor. (22) In the system of (21), the non-insulated superconducting magnet comprises a first conductive plate having a first groove and a first high-temperature superconductor (HTS) tape stack including a first plurality of circumferential circuits disposed within the first groove, and when a first current is applied to the non-insulated superconducting magnet, a first resistance between each of the first plurality of circumferential circuits of the first HTS tape stack is less than 1 megaohm. (23) In the system of (22), the non-insulated superconducting magnet further includes a second conductive plate having a second groove and a second HTS tape stack including a second plurality of circumferential circuits disposed in the second groove, and the first HTS tape stack forms a conductive connection with the second HTS tape stack. (24) In the system of (23), the non-insulated superconducting magnet comprises a plurality of conductive plates including a first conductive plate and a second conductive plate, and the plurality of conductive plates are arranged in a stacked configuration. (25) In the system of (24), the non-insulated superconducting magnet comprises a conductor including a first HTS tape stack and a second HTS tape stack, the conductor entering the second conductive plate from the first conductive plate at a first point on the second conductive plate, the first conductive plate being disposed below the second conductive plate in a stacked configuration, the conductor exiting the second conductive plate at a second point on the second conductive plate to a third conductive plate among the plurality of conductive plates, the third conductive plate being disposed above the second conductive plate in a stacked configuration, a second plurality of circuit lines of the second conductive plate extending from the first point to a second point, the conductor including a first extension portion at the first point, the first extension portion extending in a direction opposite to a direction in which the second plurality of circuit lines extend from the first point to the second point, and the conductor including a second extension portion at the second point, the second extension portion extending in a direction opposite to a direction in which the second plurality of circuit lines extend from the second point to the first point. (26) In the system of (24), the non-insulated superconducting magnet further comprises an electrically insulating material between adjacent plates of the plurality of conductive plates. (27) A superconducting non-insulated magnet comprising: a plate; a plurality of circumferential circuits of superconducting material within the plate, the plurality of circumferential circuits extending from a first terminal having a first electrical connection extending outside the plate to a second terminal having a second electrical connection extending outside the plate; a first extension including a first partial circumferential circuit of superconducting material extending beyond the first terminal; and a second extension including a second partial circumferential circuit of superconducting material extending beyond the second terminal. In the superconducting non-insulated magnet of (28)(27), the first and second extensions have approximately the same length. (29) In the superconducting non-insulated magnet of any one of (27) to (28), the first and second extension portions have different lengths. (30) In the superconducting non-insulated magnet of any one of (27) to (29), the superconducting material is arranged in a spiral configuration including a plurality of circumferential circuits, and the first and second extensions each have a length approximately half that of one of the plurality of circumferential circuits. (31) In the superconducting non-insulated magnet of any one of (27) to (30), the first and second extension portions each have a length approximately 1 / 4 of the length of one of the plurality of circumferential circuits. (32) In the superconducting non-insulated magnet of any one of (27) to (31), the first and second terminals are arranged on opposite sides of the upper surface of the plate. (33) In the superconducting non-insulated magnet of any one of (27) to (32), the first extension portion has a width that varies along the length of the first extension portion, and the second extension portion has a width that varies along the length of the second extension portion. (34) The superconducting non-insulated magnet according to any one of (27) to (33), further comprising a plurality of plates, the plurality of plates including the aforementioned plates. (35) In the superconducting non-insulated magnet of (34), a plurality of plates are arranged in a stacked configuration. (36) The superconducting non-insulated magnet of (35), further comprising an insulator disposed between adjacent plates of the plurality of plates. (37) In the superconducting non-insulated magnet of (34), the plurality of plates includes at least 10 plates. (38) In the superconducting non-insulated magnet of (34), the plurality of plates includes at least 20 plates. (39) A system comprising any one of the superconducting non-insulated magnets (27) to (38) and a controller, the controller configured to operate the superconducting non-insulated magnet by applying a first current to the superconducting non-insulated magnet. In the system of (40)(39), when the controller applies a first current to the superconducting non-insulated magnet, no current flows through the first and second extensions. (41) The system of (40), wherein the controller is further configured to induce a quench in the superconducting, non-insulated magnet at least in part by applying a second current to the magnet, the second current being different from the first current, the second current being greater in magnitude than the first current and / or opposite in direction to the first current.

[0074] While various aspects and embodiments of the technology set forth in this disclosure have been described, it should be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to fall within the spirit and scope of the technology described herein. For example, those skilled in the art will readily envision a variety of other means and / or structures for performing the functions and / or obtaining one or more of the results and / or advantages described herein. Each of such variations and / or modifications is deemed to fall within the scope of the embodiments described herein. Aspects described in one embodiment may be combined in any manner with aspects described in other embodiments. Those skilled in the art will be able to ascertain or ascertain using no more than routine experimentation, many equivalents to the specific embodiments described herein. It should therefore be understood that the foregoing embodiments have been presented by way of example only, and that, within the scope of the appended claims and their equivalents, embodiments of the invention may be practiced other than as specifically described. Additionally, any combination of two or more features, systems, articles, materials, kits, and / or methods described herein that are not mutually inconsistent is intended to be within the scope of the present disclosure.

[0075] The above-described embodiments may be implemented in any of numerous ways. One or more aspects and embodiments of the present disclosure involving the execution of a process or method may utilize program instructions executable by a device (e.g., a computer, processor, or other device) to perform the process or method or to control the execution of the process or method. In this regard, various inventive concepts may be embodied as a non-transitory computer-readable storage medium (or multiple computer-readable storage media) having one or more programs encoded thereon (e.g., computer memory, one or more floppy disks, compact disks, optical disks, magnetic tapes, flash memory, circuitry in field programmable gate arrays or other semiconductor devices, or other tangible computer storage media). When the programs are executed on one or more computers or other processors, they perform methods that implement one or more of the various embodiments described above. The one or more computer-readable media may be portable, allowing the stored program or programs to be loaded into one or more different computers or other processors to implement various of the above-described aspects.

[0076] The terms "program" or "software" are used herein in a generic sense to refer to any form of computer code or set of computer-executable instructions that can be used to program a computer or other processor to implement various aspects described above. Additionally, according to one aspect, one or more computer programs, when executed, perform the methods of the present disclosure, but need not reside on a single computer or processor, but may be modularly distributed among several different computers or processors to implement various aspects of the present disclosure.

[0077] Computer-executable instructions may be in many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Typically, the functionality of the program modules may be combined or distributed as desired in various embodiments.

[0078] Data structures may also be stored in any suitable form on a computer-readable medium. For ease of illustration, a data structure may be shown as having fields related by location in the data structure. Such relationships may equally be achieved by specifying the storage of fields by location in a computer-readable medium, with these locations conveying the relationship between the fields. However, any suitable mechanism may be used to establish relationships between information in fields of a data structure, including through the use of pointers, tags, or other mechanisms that establish relationships between data elements.

[0079] The above-described embodiments of the present technology can be implemented in any of numerous ways. For example, embodiments can be implemented using hardware, software, or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether the processors are located on one computer or distributed across multiple computers. It should be appreciated that any component or collection of components that performs the above-described functions can be collectively considered a controller that controls the above-described functions. The controller can be implemented in numerous ways, such as by dedicated hardware or by general-purpose hardware (e.g., one or more processors) programmed with microcode or software to perform the above-enumerated functions, and can also be implemented in a combination of ways when the controller corresponds to multiple components of a system.

[0080] It should further be appreciated that a computer can be embodied in any of a number of forms, such as, by way of non-limiting example, a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer. In addition, a computer can be embedded in devices that are not generally considered computers but that have suitable processing capabilities. Such devices include personal digital assistants (PDAs), smartphones, or any other suitable portable or fixed electronic device.

[0081] A computer may also have one or more input and output devices. These devices may be used, among other things, to present a user interface. Examples of output devices that may be used to provide a user interface include a printer or display screen for visual display of output and a speaker or other sound-generating device for audible presentation of output. Examples of input devices that may be used in a user interface include keyboards and pointing devices such as mice, touch pads, and digitizing tablets. As another example, a computer may receive input information through speech recognition or in other audible formats.

[0082] Such computers may be interconnected in any suitable manner by one or more networks, including local area networks, or wide area networks such as enterprise networks and intelligent networks (IN), or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol, and may include wireless networks, wired networks, or fiber optic networks.

[0083] Also, as described, some aspects may be embodied as one or more methods. Acts performed as part of a method may be ordered in any suitable manner. Thus, embodiments may be constructed in which acts are performed in an order different from that shown, and in which some acts may be performed simultaneously even though they are shown as sequential acts in the exemplary embodiment.

[0084] It should be understood that all definitions defined and used herein supersede dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0085] As used in this specification and the claims, the indefinite articles "a" and "an" should be understood to mean "at least one" unless clearly indicated to the contrary.

[0086] When the term "and / or" is used in the specification and claims, it should be understood to mean "either or both" of the elements so grouped, i.e., elements present conjunctively in some cases and disjunctively in other cases. Multiple elements listed with "and / or" should be construed in the same manner, i.e., "one or more" of the elements so grouped. Other elements, whether related or unrelated to those elements specifically identified, may optionally be present beyond the elements specifically identified by the "and / or" clause. Thus, as a non-limiting example, a reference to "A and / or B," when used in conjunction with open-ended language such as "comprising," may, in one embodiment, refer to A only (optionally including elements other than B); in another embodiment, refer to B only (optionally including elements other than A); in yet another embodiment, refer to both A and B (optionally including other elements); and so forth.

[0087] The phrase "at least one," when used in this specification and claims with reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but does not necessarily include at least one of every element specifically listed in the list of elements, and does not exclude any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than those specifically identified in the list of elements to which the phrase "at least one" refers, whether related or unrelated to the specifically indicated elements. Thus, as one non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B" and "at least one of A and / or B") can mean, in one embodiment, at least one, and optionally more than one, A, and no B (and optionally including elements other than B); in another embodiment, at least one, and optionally more than one, B, and no A (and optionally including elements other than A); in yet another embodiment, at least one A, optionally including more than one A, and at least one B, optionally including more than one B (and optionally including other elements), etc.

[0088] Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. When used herein, the words "including," "comprising," "having," "containing," "involving," and variations thereof are meant to encompass the items listed thereafter, and equivalents thereof, as well as additional items.

[0089] In the claims and the foregoing specification, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," "composed of," and the like, shall be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively.

[0090] The terms "substantially," "approximately," and "about" can be used to mean, in some embodiments, within ±20% of a target value, in some embodiments, within ±10% of a target value, in some embodiments, within ±5% of a target value, and in some embodiments, within ±2% of a target value. The terms "approximately" and "about" may include the target value.

[0091] The use of ordinal numbers such as "first," "second," "third," etc. to modify claim elements in the claims does not, by itself, imply any priority, precedence, or order of one claim element over another, i.e., the chronological order in which the acts of a method are performed, but is merely used to distinguish one claim element having a particular name from another element having the same name (except for the use of the ordinal number) and is used to distinguish the claim elements. [Explanation of symbols]

[0092] 102 Plate 104 Groove 106 Conductor 108A Winding lead-out bonding pad 108B Winding entry pad 109 Notch 110 Loop Line 112 Insulator 114 Conductive path entrance 115 Conductive path exit 116A OD circuit line 116B ID loop line 1200 Control Circuit 1202 processor 1204 Drive Electronic Circuit 1206 Magnet coil 1208 Switch

Claims

1. 1. A method of inducing a quench in a non-insulated superconducting magnet, the method comprising: operating the non-insulated superconducting magnet by applying a first current to the non-insulated superconducting magnet; and inducing a quench at least partially within the non-insulated superconducting magnet by applying a second current to the non-insulated superconducting magnet, the second current being opposite in direction to the first current.

2. 2. The method of claim 1, wherein the magnitude of the second current is greater than the magnitude of the first current.

3. 3. The method of claim 2, wherein the magnitude of the second current is at least twice the magnitude of the first current.

4. 4. The method according to claim 1, further comprising the step of opening up the non-insulated superconducting magnet after applying the first current to the non-insulated superconducting magnet and before applying the second current to the non-insulated superconducting magnet.

5. 5. The method according to claim 1, wherein the second current is applied to the non-insulated superconducting magnet so as to induce a radial current in the non-insulated superconducting magnet.

6. 6. The method according to claim 1, wherein the non-insulated superconducting magnet includes a plurality of circuit lines, and when the first current is applied to the non-insulated superconducting magnet, a resistance between each of the plurality of circuit lines is less than 1 megaohm.

7. 7. The method according to claim 1, wherein the step of applying the second current to the non-insulated superconducting magnet is performed by a control circuit of the non-insulated superconducting magnet in response to the control circuit receiving a command to disable the non-insulated superconducting magnet or in response to the control circuit making a decision to shut down the non-insulated superconducting magnet.

8. The method of any one of claims 1 to 7, wherein the non-insulated superconducting magnet comprises a high temperature superconductor.

9. 10. The method of claim 8, wherein the non-insulated superconducting magnet comprises a first conductive plate having a first groove and a first high temperature superconductor (HTS) tape stack including a first plurality of circumferential circuits disposed within the first groove, and wherein when the first current is applied to the non-insulated superconducting magnet, a resistance between each of the first plurality of circumferential circuits of the first HTS tape stack is less than 1 megaohm.

10. 10. The method of claim 9, wherein the non-insulated superconducting magnet further comprises a second conductive plate having a second groove and a second HTS tape stack including a second plurality of circumferential circuits disposed in the second groove, and wherein the first HTS tape stack forms a conductive connection with the second HTS tape stack.

11. 11. The method of claim 10, wherein the non-insulated superconducting magnet comprises a plurality of conductive plates, including a first conductive plate and a second conductive plate, the plurality of conductive plates arranged in a stacked configuration.

12. 12. The method of claim 11, wherein the non-insulated superconducting magnet comprises a conductor including a first HTS tape stack and a second HTS tape stack, the conductor entering the second conductive plate from the first conductive plate at a first point on the second conductive plate, the first conductive plate being disposed below the second conductive plate in a stacked configuration, the conductor exiting the second conductive plate at a second point on the second conductive plate to a third conductive plate in a plurality of conductive plates, the third conductive plate being disposed above the second conductive plate in a stacked configuration, a second plurality of circuit circuits of the second conductive plate extending from the first point to a second point, the conductor including a first extension at the first point, the first extension extending in a direction opposite to a direction in which the second plurality of circuit circuits extend from the first point to the second point, and the conductor including a second extension at the second point. wherein the second extension extends in a direction opposite to the direction in which the second plurality of circumferential lines extend from the second point to the first point.

13. 12. The method of claim 11, wherein the non-insulated superconducting magnet further comprises an electrically insulating material between adjacent plates of the plurality of electrically conductive plates.

14. 1. A system for inducing a quench in a non-insulated superconducting magnet, the system comprising: a non-insulated superconducting magnet; and a controller, the controller configured to operate the non-insulated superconducting magnet by applying a first current to the magnet and to induce a quench in the magnet at least in part by applying a second current to the magnet, the second current being opposite in direction to the first current.

15. 15. The system of claim 14, wherein the magnitude of the second current is greater than the magnitude of the first current.

16. 16. The system of claim 15, wherein the magnitude of the second current is at least twice the magnitude of the first current.

17. 17. The system according to any one of claims 14 to 16, wherein the controller is further configured to open-circuit the non-insulated superconducting magnet after applying the first current to the non-insulated superconducting magnet and before applying the second current to the non-insulated superconducting magnet.

18. 18. The system of claim 14, wherein the controller is configured to apply the second current to the non-insulated superconducting magnet so that a radiation current is induced in the non-insulated superconducting magnet.

19. 19. The system according to any one of claims 14 to 18, wherein the non-insulated superconducting magnet includes a plurality of circumferential circuits, and when the first current is applied to the non-insulated superconducting magnet, a resistance between each of the plurality of circumferential circuits is less than 1 megaohm.

20. 20. The system of any one of claims 14 to 19, further comprising a control circuit configured to apply the second current to the non-insulated superconducting magnet, the control circuit configured to apply the second current to the non-insulated superconducting magnet in response to receiving a command to disable the non-insulated superconducting magnet or in response to making a decision to stop the non-insulated superconducting magnet.

21. 21. The system of any one of claims 14 to 20, wherein the non-insulated superconducting magnet comprises a high temperature superconductor.

22. 22. The system of claim 21, wherein the non-insulated superconducting magnet comprises a first conductive plate having a first groove and a first high temperature superconductor (HTS) tape stack including a first plurality of circumferential circuits disposed in the first groove, wherein a first resistance between each of the first plurality of circumferential circuits of the first HTS tape stack is less than 1 megaohm when the first current is applied to the non-insulated superconducting magnet.

23. 23. The system of claim 22, wherein the non-insulated superconducting magnet further comprises a second conductive plate having a second groove and a second HTS tape stack including a second plurality of circumferential circuits disposed in the second groove, the first HTS tape stack forming a conductive connection with the second HTS tape stack.

24. 24. The system of claim 23, wherein the non-insulated superconducting magnet comprises a plurality of conductive plates including a first conductive plate and a second conductive plate, the plurality of conductive plates arranged in a stacked configuration.

25. 25. The system of claim 24, wherein the non-insulated superconducting magnet comprises a conductor including a first HTS tape stack and a second HTS tape stack, the conductor entering the second conductive plate from the first conductive plate at a first point on the second conductive plate, the first conductive plate being disposed below the second conductive plate in a stacked configuration, the conductor exiting the second conductive plate at a second point on the second conductive plate to a third conductive plate in the plurality of conductive plates, the third conductive plate being disposed above the second conductive plate in a stacked configuration, a second plurality of circuit circuits of the second conductive plate extending from a first point to a second point, the conductor including a first extension at the first point, the first extension extending in a direction opposite to a direction in which the second plurality of circuit circuits extend from the first point to the second point, and the conductor including a second extension at the second point. , wherein the second extension extends in a direction opposite to the direction in which the second plurality of circumferential circuits extend from the second point to the first point.

26. 25. The system of claim 24, wherein the non-insulated superconducting magnet further comprises an electrically insulating material between adjacent plates of the plurality of electrically conductive plates.

27. 1. A superconducting non-insulated magnet comprising: a plate; a plurality of circumferential circuits of superconducting material in grooves in the plate, the plurality of circumferential circuits extending from a first terminal having a first electrical connection extending outside the plate to a second terminal having a second electrical connection extending outside the plate; a first extension including a first partial circumferential circuit of superconducting material extending beyond the first terminal; and a second extension including a second partial circumferential circuit of superconducting material extending beyond the second terminal.

28. 28. The superconducting, non-insulated magnet of claim 27, wherein the first and second extensions are approximately equal in length.

29. 29. The superconducting, non-insulated magnet according to claim 27, wherein the first and second extensions have different lengths.

30. 30. The superconducting, non-insulated magnet of any one of claims 27 to 29, wherein the superconducting material is arranged in a spiral configuration including a plurality of circumferential circuits, and the first and second extensions each have a length approximately half that of one of the plurality of circumferential circuits.

31. 31. The superconducting non-insulated magnet according to any one of claims 27 to 30, wherein the first and second extensions each have a length approximately 1 / 4 of the length of one of the plurality of circumferential circuits.

32. 32. The superconducting non-insulated magnet according to claim 27, wherein the first and second terminals are disposed on opposite sides of the upper surface of the plate.

33. 33. The superconducting non-insulated magnet according to any one of claims 27 to 32, wherein the first extension portion has a width that varies along the length of the first extension portion, and the second extension portion has a width that varies along the length of the second extension portion.

34. The superconducting non-insulated magnet according to any one of claims 27 to 33, further comprising a plurality of plates, wherein the plurality of plates includes the plate.

35. 35. The superconducting, non-insulated magnet of claim 34, wherein the plurality of plates are arranged in a stacked configuration.

36. 36. The superconducting, non-insulated magnet of claim 35, further comprising an insulator disposed between adjacent plates of the plurality of plates.

37. 35. The superconducting, non-insulated magnet of claim 34, wherein the plurality of plates comprises at least 10 plates.

38. 35. The superconducting, non-insulated magnet of claim 34, wherein the plurality of plates comprises at least 20 plates.

39. A system comprising: the superconducting, non-insulated magnet according to any one of claims 27 to 38; and a controller, wherein the controller is configured to operate the superconducting, non-insulated magnet by applying a first current to the superconducting, non-insulated magnet.

40. 40. The system of claim 39, wherein when the controller applies the first current to the superconducting, non-insulated magnet, no current flows through the first and second extensions.

41. 41. The system of claim 40, wherein the controller is further configured to induce a quench in the superconducting, non-insulated magnet at least in part by applying a second current to the magnet, wherein the second current is different from the first current, the second current being greater in magnitude than the first current and / or opposite in direction to the first current.

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