Field charging system for superconducting magnets

Abstract

A superconducting circuit for a superconducting magnet includes a first temperature zone, a second temperature zone, at least one first member, at least one second member, and a field charging system. The first temperature zone defines a first temperature. The second temperature zone defines a second temperature that is higher than the first temperature. The at least one first member is positioned within the first temperature zone. At least one second component is positioned within the second temperature zone. The field charging system includes at least one flexible connection electrically coupling the first member and the second member. The at least one flexible connection allows displacement and movement between the first member and the second member due to thermal expansion and contraction caused by different first and second temperatures.

Description

[0001] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was made with government support under Contract No. DE-EE0008787 awarded by the Department of Energy (DOE). The government has certain rights in this invention. Technical Field

[0003] The present disclosure relates to superconducting magnets and, more particularly, to field charging systems for superconducting magnets such as used in superconducting generators. Background Art

[0004] Superconducting machines generally include superconducting magnets made up of coils of superconducting circuits. In their superconducting state, superconducting circuits have no resistance and can therefore conduct much greater currents than ordinary wires, thereby generating strong magnetic fields. As a result, superconducting magnets can generate larger magnetic fields than non-superconducting electromagnets, and because no energy is dissipated as heat in the windings, they are less expensive to operate. As a result, superconducting magnets are commonly used in magnetic resonance imaging (MRI) machines and in scientific equipment such as nuclear magnetic resonance (NMR) spectrometers, generators, mass spectrometers, fusion reactors, and particle accelerators.

[0005] During operation, the superconducting magnet windings must be cooled below their critical temperature (i.e., the temperature at which the winding material changes from a normal resistive state and becomes a superconductor). Typically, the windings are cooled to a temperature significantly below their critical temperature, because lower temperatures enable superconducting windings to withstand higher currents and magnetic fields without returning to their non-superconducting state. Therefore, liquid cooling or mechanical cooling is usually used to keep the windings at a temperature sufficient to maintain superconductivity. In liquid cooling, a liquid cryogen (e.g., helium, hydrogen, argon, or other, depending on the operating temperature) is used as a coolant, which has a boiling point well below the critical temperature of most winding materials. For example, helium boils at 4.2 Kelvin, well below the critical temperature of 9 Kelvin of niobium titanium (NbTi) superconducting wire. Therefore, the superconducting magnet and the liquid cryogen are contained in an insulated container called a cryostat. Alternatively, mechanical cooling includes cooling the superconducting magnet using two-stage mechanical refrigeration.

[0006] In addition, during the operation of the superconducting magnet, once the magnet is powered, the winding can be short-circuited with a superconducting material piece. The short-circuiting is sometimes also referred to as a continuous switch, which generally refers to a superconducting material piece that is connected across the winding ends and attached to the inside of the magnet of the small heater. Therefore, the winding becomes a closed superconducting loop, the power supply can be turned off, and a continuous current can flow for an extended period of time to maintain the magnetic field. The advantage of this continuous mode is that the stability of the magnetic field is better than that achieved with the best power supply, and no energy is required to power the winding. For example, a superconducting switch is generally wound in a bifilar parallel winding mode to minimize its inductance, so that in the superconducting state, it exhibits zero resistance and negligible inductance.

[0007] Therefore, when the superconducting magnet is first switched on, the switch is heated above its transition temperature, making the switch resistive. To operate in continuous mode, the supply current is adjusted until the desired magnetic field is obtained, and then the heater is turned off. The continuous switch cools to its superconducting temperature, short-circuiting the windings. Then, the power can be turned off.

[0008] To further assist the system, the various components of the superconducting magnet and switch may be arranged in separate zones within the superconducting machine in order to reduce undesirable heat transfer between components designed to be maintained at cold or hot temperatures. However, consideration must be given to displacement and movement between the various components of the superconducting magnet due to thermal expansion and contraction, as well as dynamic load changes due to the transition of the magnetic field to continuous mode.

[0009] Accordingly, the present disclosure is directed to an improved field charging system for superconducting circuits that addresses the above-mentioned problems. Summary of the invention

[0010] Aspects and advantages of the present disclosure will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the present disclosure.

[0011] In one aspect, the present disclosure is directed to a superconducting circuit for a superconducting magnet. The superconducting circuit includes a first temperature zone, a second temperature zone, at least one first member, at least one second member, and a field charging system. The first temperature zone defines a first temperature. The second temperature zone defines a second temperature, the second temperature being higher than the first temperature. At least one first member is positioned within the first temperature zone. At least one second member is positioned within the second temperature zone. The field charging system includes at least one flexible connector electrically coupling the first member and the second member. The at least one flexible connector allows displacement and movement between the first member and the second member due to thermal expansion and contraction caused by different first and second temperatures.

[0012] In an embodiment, the first component includes a plurality of superconducting coils, and the second component includes at least one of a thermal shield surrounding the plurality of superconducting field coils. In addition, the field charging system is configured to energize the plurality of superconducting coils.

[0013] In a further embodiment, the field charging system further comprises a plurality of high current leads and a superconducting switch.

[0014] In additional embodiments, the plurality of high current leads further include a pair of high temperature superconductor (HTS) leads and a pair of resistor leads, the pair of resistor leads being one or more power feedthroughs extending through the vacuum vessel and connected to the pair of HTS leads via at least one flexible connector, the pair of HTS leads being connected to a plurality of superconducting field coils and a superconducting switch.

[0015] In other embodiments, the superconducting switch is mounted on a cold plate that is mechanically and thermally coupled to a support structure of the plurality of superconducting field coils. In addition, a pair of HTS leads are secured to the cold plate.

[0016] In yet further embodiments, the connection between the pair of HTS leads and the pair of resistor leads includes at least one flexible connector and a thermal plate.

[0017] In other additional embodiments, the pair of resistor leads includes copper, brass, phosphor bronze, or combinations thereof.

[0018] In further additional embodiments, the first temperature is less than about 10 Kelvin (K), and the second temperature is between about 35K and about 55K.

[0019] In yet other embodiments, the superconducting circuit further comprises a third temperature zone defining a third temperature higher than the first temperature and the second temperature. In addition, a third member is placed in the third temperature zone and is connected to the second member via a second flexible connector of the at least one flexible connector.

[0020] In yet another embodiment, the second component includes a thermal shield having at least one electrical component disposed therein, and the third component includes a vacuum vessel including the at least one electrical component disposed therein.

[0021] In a further embodiment, at least one flexible connector comprises a braided wire.

[0022] On the other hand, the present disclosure is directed to a field charging system for energizing multiple superconducting coils of a superconducting magnet. The field charging system includes at least one high temperature superconductor (HTS) lead, a power source, and at least one flexible connector. The HTS lead connects a first temperature and a second temperature, the second temperature being different from the first temperature. The power source is at a different third temperature for providing power to the field charging system to energize the multiple superconducting coils. At least one flexible connector is electrically connected between at least one HTS lead at a first temperature and the power source at a second temperature. In addition, at least one flexible connector allows displacement and movement of components of the field charging system due to thermal expansion and contraction caused by the different first and second temperatures.

[0023] In one embodiment, the power supply comprises one or more power feed-through lines extending through the vacuum vessel and the thermal shield of the superconducting magnet.

[0024] In another embodiment, one or more rod members are coupled to one or more power feed-through lines at least partially within the heat shield.

[0025] In a further embodiment, the at least one flexible connector includes at least one first flexible connector and at least one second flexible connector, wherein the at least one first flexible connector is coupled to one or more rod components and a first location on at least one hot plate, and the at least one second flexible connector is coupled to a second location on at least one hot plate and at least one HTS lead.

[0026] In yet another embodiment, the field charging system further includes a superconducting switch, at least one HTS lead and the superconducting switch coupled to the plurality of superconducting coils.

[0027] In yet another aspect, the present disclosure is directed to a method for energizing a plurality of superconducting coils of a superconducting magnet. The method includes coupling a field charging system to a plurality of superconducting coils and to at least one additional component of the superconducting magnet, the plurality of superconducting coils and the at least one additional component being maintained at different temperatures, the field charging system having a power source, at least one high temperature superconductor (HTS) lead, and at least one flexible connector electrically coupled between the power source and the at least one HTS lead. The method further includes providing power to the field charging system via the power source to energize the plurality of superconducting coils. The at least one flexible connector allows displacement and movement of components of the field charging system due to thermal expansion and contraction caused by different temperatures.

[0028] In another embodiment, the method further includes coupling the one or more rod components to the one or more power feed-through lines.

[0029] In yet another embodiment, the at least one flexible connector includes at least one first flexible connector and at least one second flexible connector. In addition, the method further includes coupling the at least one first flexible connector to the one or more rod components at a first location on the at least one thermal plate, and coupling the at least one second flexible connector to a second location on the at least one thermal plate and the at least one HTS lead.

[0030] These and other features, aspects and advantages of the present disclosure will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and together with the description, serve to explain the principles of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] A complete and enabling disclosure of the present disclosure, including the best mode thereof, for one of ordinary skill in the art is set forth in the specification, which refers to the accompanying drawings, in which:

[0032] Figure 1 shows a perspective view of one embodiment of a superconducting magnet according to the present disclosure;

[0033] Figure 2 Shows Figure 1 A transparent perspective view of an embodiment of a superconducting magnet, particularly showing the internal components of the superconducting magnet;

[0034] Figure 3 A perspective view showing one embodiment of a superconducting switch of a superconducting magnet according to the present disclosure;

[0035] Figure 4 Shows Figure 3 Detailed view of a superconducting switch;

[0036] Figure 5 Shows Figure 4 A detailed perspective view of a superconducting switch of FIG. 1 , particularly showing a superconducting winding and a thermally conductive component of the superconducting switch thermally coupled to a conductive rod;

[0037] Figure 6 shows a detailed perspective view of another embodiment of a superconducting switch according to the present disclosure, particularly showing a superconducting winding and a thermally conductive component of the superconducting switch electrically coupled to a tube;

[0038] Figure 7 shows a simplified schematic diagram of a superconducting magnet according to the present disclosure;

[0039] Figure 8 A circuit diagram showing an embodiment of a field charging system for a superconducting magnet according to the present disclosure is shown;

[0040] Fig. 9A schematic diagram showing an embodiment of various components of a field charging system for a superconducting magnet according to the present disclosure;

[0041] Fig.10 A partial perspective view showing various components of a field charging system for a superconducting magnet according to the present disclosure; and

[0042] Fig.11 A flow chart of an embodiment of a method for energizing a plurality of superconducting coils of a superconducting magnet according to the present disclosure is shown. DETAILED DESCRIPTION

[0043] Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are shown in the accompanying drawings. Each example is provided by way of illustration of the present disclosure, without limiting the present disclosure. Indeed, it will be apparent to those skilled in the art that various modifications and variations may be made in the present disclosure without departing from the scope of the present disclosure. For example, a feature shown or described as part of an embodiment may be used in conjunction with another embodiment to produce yet another embodiment. Therefore, it is intended that the present disclosure covers such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0044] In general, the present disclosure is directed to a superconducting circuit with a flexible field charging system for a superconducting magnet, such as a superconducting generator. In one embodiment, for example, the superconducting circuit may include a first temperature zone defining a first temperature and a second temperature zone defining a second temperature higher than the first temperature. The superconducting circuit may also include a first member positioned within the first temperature zone and a second member positioned within the second temperature zone. Thus, the field charging system of the superconducting circuit includes a flexible connector electrically connecting the first member and the second member. Therefore, the flexible connector allows displacement and movement between the first member and the second member due to thermal expansion and contraction caused by different first and second temperatures. Thus, the superconducting circuit allows temperature differences between zones of the superconducting magnet and reduces the possibility of damage to the superconducting magnet thereby.

[0045] Now referring to the accompanying drawings, Figures 1 to 3 A perspective view of one embodiment of a superconducting magnet 10 according to the present disclosure is shown. Such superconducting magnets may be used in a variety of applications including, but not limited to, magnetic resonance imaging (MRI) machines, NMR spectrometers, generators (e.g., such as wind turbine generators), mass spectrometers, fusion reactors, particle accelerators, levitation, guidance and propulsion, etc. In particular, Figure 1 shows an overall perspective view of one embodiment of a superconducting magnet 10 according to the present disclosure; Figure 2 shows a transparent perspective view of one embodiment of a superconducting magnet 10 according to the present disclosure; and Figure 3 An internal perspective view of one embodiment of a superconducting magnet 10 according to the present disclosure is shown.

[0046] In particular, if Figure 2 , a superconducting magnet 10 includes an insulated container 12, generally referred to as a cryostat. As used herein, a cryostat generally refers to a container that contains a cryogenic cooling system. Figure 3 , the thermally insulated container 12 of the superconducting magnet 10 includes a superconducting circuit 16 having one or more superconducting coils 23 located inside the thermally insulated container 12 and supported by an internal structure 29. Thus, in such embodiments, the thermally insulated container 12 isolates the superconducting circuit(s) 16 so that the wire(s) can be cooled to near absolute zero, for example, to 10 Kelvin (K) and preferably to 4K. For example, as Figure 3 , the insulated container 12 may include a plurality of conduits 21 that deliver liquid cryogen (e.g., helium, hydrogen, argon, or other, depending on the operating temperature) from the tank 15 to the internal structure 29 and / or the entire inner wall of the insulated container 12. In addition, in one embodiment, the interior portion of the insulated container 12 includes a vacuum container 13 and an insulated cover 36 ( Figure 7 ), the insulation cover 36 can intercept thermal radiation and convection between the external environment and the cold components within the insulated container 12, thereby also minimizing radiant heat transfer.

[0047] More particularly, as shown, the superconducting circuit(s) 16 may be arranged in a coil shape and may be configured to generate a magnetic field. Figure 1 As particularly shown in FIG. 1 , the superconducting magnet 10 further comprises a power supply 18 connected to a field charging system 20 for energizing the superconducting circuit(s) 16 .

[0048] Thus, in its superconducting state, the superconducting circuit(s) 16 have no resistance and can therefore conduct much greater currents than ordinary wires, thereby generating strong magnetic fields. Furthermore, during operation, the superconducting circuit(s) 16 must be cooled below its critical temperature, at which the wire material transitions from its normal resistive state and becomes a superconductor. Typically, the superconducting circuit(s) 16 are cooled to a temperature significantly below its critical temperature, because the lower the temperature, the better the superconducting windings work: the higher the currents and magnetic fields they can withstand without returning to their non-superconducting state.

[0049] Therefore, if Figures 1 to 3 In the embodiment shown in FIG. 1 , the superconducting magnet 10 may further include a cooling system 14 for providing liquid cooling to cool the superconducting circuit(s) 16. More specifically, as shown, the cooling system 14 may include one or more cooling tanks 15 ( Figure 3 ). For example, in one embodiment, the cooling medium 17 may be liquid helium, which has a boiling point of 4.2 Kelvin, which is much lower than the critical temperature of the wire material.

[0050] In one operating mode of the superconducting magnet 10, once the magnet is powered, the (multiple) superconducting circuits 16 can be short-circuited with a superconducting material piece. In such embodiments, for example, the short circuit can be performed by the field charging system 20 via a superconducting switch 25 (sometimes referred to as a continuous switch). In other words, the superconducting switch 25 of the field charging system 20 generally refers to a superconducting material piece inside the superconducting magnet 10, which is connected across the winding ends of the (multiple) superconducting circuits 16, where the heater can raise its temperature above the transition temperature of the wire. This is because the superconducting switch generally exists in a low-temperature superconducting state and is generally wound in a bifilar winding manner to minimize its inductance, so it exhibits zero resistance and negligible inductance in the superconducting state.

[0051] In addition, if Figure 4 As shown in FIG. 1 , a heat exchanger 30, such as a finned copper heat exchanger, may be included to allow the superconducting switch 25 of the field charging system 20 to be cooled by liquid helium. Thus, when the heat exchanger 30 is closed and the superconducting switch 25 of the field charging system 20 is cooled below its transition temperature, the superconducting circuit(s) 16 become a closed superconducting loop, so the power supply 18 can be turned off, and a continuous current will flow for an extended period of time to maintain the magnetic field. Thus, the advantage of this continuous mode is that the stability of the magnetic field is better than that achievable with an optimal power supply, and no energy is required to power the windings.

[0052] In addition, when the superconducting magnet 10 is first turned on, the superconducting switch 25 of the field charging system 20 is heated to above its transition temperature, so that the superconducting switch 25 of the field charging system 20 has resistance. To achieve this, the power supply 18 is connected across a pair of current leads, which are electrically connected to the superconducting coil 23 and the field charging system 20. The current leads further include at least one resistive current lead and another high temperature superconductor (HTS) current lead. The supply current will be adjusted until the desired magnetic field is obtained, and then the heater will be turned off. The superconducting switch 25 of the field charging system 20 cools to its superconducting temperature, thereby short-circuiting the (multiple) superconducting circuits 16. Then, the power supply 18 can be turned off.

[0053] Reference now Figures 4 to 6 The superconducting switch 25 of the field charging system 20 includes a superconducting winding 22 and a heat-conducting component 24. For example, in one embodiment, the superconducting winding may be a superconducting winding wound in parallel with two wires to achieve minimum inductance. In addition, in one embodiment, the heat-conducting component 24 includes a first end 26 thermally coupled to the superconducting winding 22 and a second end 28 thermally coupled to the cooling tank 15. For example, Figure 4 As shown in FIG. 1 , the heat exchanger 30 may be installed in the cooling tank 15 and thermally connected to the field charging system 20 via a heat conducting rod 32 (such as a copper rod) fixed to the tank wall 19 ( Figure 3 ) (e.g., via brazing). In addition, Figure 4 and Figure 5 , an additional support structure 34 may be mounted to the heat conducting rod 32, for example, via soldering, and the second end 28 of the heat conducting component 24 may be fixed to the additional support structure 34. In an alternative embodiment, as Figure 6 , the thermally conductive component 24 can be mounted to one of the conduits 21. In such embodiments, the thermally conductive component 24 can be mounted to the conduit 21 using one or more braided copper straps that can be secured to the thermally conductive component 24 and the conduit 21.

[0054] Reference now Figure 7 , a simplified schematic diagram of a superconducting magnet 10 is shown. More specifically, as shown, the superconducting magnet 10 generally includes a cooling system 14, a vacuum vessel 13, a cold block 38, a heat shield 36 between the cold block 38 and the vacuum vessel 13, and a cryocooler 40. In addition, as shown, the cooling system 14 can generally be arranged with the heat shield 36 of the superconducting magnet 10. In such embodiments, for example, the cold block 38 can be a stationary component, such as a field winding assembly in which an armature winding assembly rotates. In addition, as an example, the vacuum vessel 13 can be a non-rotating component supporting a magnetic field winding assembly. Therefore, in such embodiments, the rotatable component can be oriented to rotate relative to the non-rotatable component during operation of the superconducting magnet 10. In such embodiments, the heat shield 36 surrounds the cold block 38 and intercepts and / or blocks radiation from the vacuum vessel 13 (as indicated by arrow 42). Furthermore, as shown, heat is removed to the cryocooler 40 via the thermal bus / busbar 44, thereby blocking most of the radiant heat from the cold block 38. Furthermore, as shown, the thermal bus / busbar 44 of such a configuration is attached to the top of the thermal shield 36 for connection to the cryocooler 40. The thermal shield 36 also intercepts heat conducted through the structural members.

[0055] Reference now Figures 8 to 10 , various views of components of a field charging system 100 for energizing superconducting coils of a superconducting magnet 10 described herein are shown. In particular, Figure 8 An embodiment of a circuit diagram 102 of a field charging system 100 according to the present disclosure is shown. Fig. 9 A schematic diagram showing an embodiment of various components of a field charging system 100 according to the present disclosure is shown, and in particular, the field charging system 100 is coupled between a superconducting coil 23 and a power source 18 via a heat shield 36 and a vacuum vessel 13 . Fig.10 A partial perspective view of various components of a field charging system 100 according to the present disclosure is shown.

[0056] like Figure 8 Specifically shown in FIG. 1 , the circuit diagram 102 generally includes a power source 18 for providing power to the field charging system 100 so as to charge the superconducting coil 23 ( Fig. 9 )(Similar to Figure 3 The superconducting coil 23 shown in FIG. 1 is energized. Figures 8 to 10 , the field charging system 100 further includes a plurality of high current leads 104, a cold block 38 including a superconducting switch assembly 106, and at least one flexible connector 108, 110. More specifically, as shown, the superconducting switch assembly 106 may generally include a superconducting switch 112 and a plurality of electrical protection diodes 114. The superconducting switch assembly 106 is electrically connected in parallel with an inductor representing the superconducting coil 23.

[0057] In addition, if Figure 8 and 9 As shown in FIG. 1 , the high current leads 104 described herein may include several types of leads, such as one or more resistor leads 118 and / or one or more HTS leads 120. In other embodiments, such as Fig.10 Specifically shown in FIG. 1 , the resistor lead wire(s) 118 may be a vacuum power feed-through wire and further include a connection to the power source 18 ( Figure 8 ), one or more conductive rods 121 extending through the heat shield 36 and / or the vacuum container 13, and / or one or more coupling members 123 fixing the (multiple) power connectors 119 to the (multiple) conductive rods 121. In addition, in one embodiment, as Fig.10 As shown in FIG. 1 , the superconducting switch 112 and (multiple) HTS leads 120 may be mounted on a cold plate 125 that is connected to a support structure ( FIG. 14 ) of the plurality of superconducting field coils 23. Fig.10 Not shown in , but in Figure 8 and 9 (shown in Figure 3) mechanical and thermal connections.

[0058] Therefore, in one embodiment, the components of the field charging system 100 are configured to span multiple components of the superconducting magnet 10 so that various components thereof can be placed in different zones with different temperatures. Figure 8117 and 122. As particularly shown in FIG. 117 , the superconducting switch assembly 106 may be located in a first zone maintained at a first temperature, as indicated by the dashed line 122 below. The first temperature zone may have a temperature of less than about 10 Kelvin (K), such as less than about 8K, such as less than about 5K. In addition, as shown, the hot end of at least one of the (multiple) HTS leads 120 may be located in a second zone maintained at a different second temperature, as indicated by the dashed lines 117 and 122 between. The cold end of the (multiple) HTS lead 120 may be connected in the first temperature zone. In such embodiments, the second temperature zone may have a higher temperature than the temperature of the first temperature zone. For example, the second temperature zone may have a temperature ranging from about 20K to about 70K, such as about 25K to about 65K, such as about 30K to about 60K, such as about 35K to about 55K. In addition, the power supply 18 and / or one or more resistive leads 118 may be located in a third zone maintained at a third temperature, as indicated by the dashed line 117 above. In certain embodiments, the third temperature zone may be a temperature higher than both the first temperature zone and the second temperature zone. For example, the third temperature zone may be close to the ambient operating temperature, such as greater than 200K, such as greater than about 250K, such as greater than about 300K.

[0059] Therefore, flexible connector(s) 108, 110 may be provided to allow displacement and movement of components of the field charging system 100 due to thermal expansion and contraction caused by the different temperatures of the first temperature zone, the second temperature zone, and the third temperature zone. Fig. 9 As particularly shown in FIG. 1 , one or more pairs of flexible connectors 108 , 110 may be electrically coupled between the superconducting coil 23 and the power source 18 and / or HTS lead(s) 120 .

[0060] In one embodiment, for example, the flexible connectors 108, 110 may include a first pair of flexible connectors 108 and a second pair of flexible connectors 110. In addition, in one embodiment, the flexible connectors 108, 110 described herein may be one or more braided wires or foil components. Fig. 9 , the field charging system 100 may also include one or more heat plates 124, such as a pair of heat plates, coupled between the first pair of flexible connectors 108 and the second pair of flexible connectors 110. For example, the first pair of flexible connectors 108 may be placed at one location or end of the one or more heat plates 124, and the second pair of flexible connectors 110 may be placed at another location or end of the one or more heat plates 124.

[0061] In one embodiment, the first temperature zone may refer to where the cold block (or superconducting coil 23) is placed. In the same embodiment, the second temperature zone may refer to where the thermal shield 36 is placed. The HTS lead wire(s) 120 may then be secured to the thermal shield 36 at the second temperature zone. Furthermore, in the same embodiment, the third temperature zone may refer to where the vacuum vessel 13 is placed. Furthermore, in the same embodiment, one or more heat plates 124 may be thermally anchored to the second temperature zone to maintain the hot end of the HTS lead wire(s) 120 at a second temperature.

[0062] In other embodiments, the HTS lead(s) 120 described herein may be formed of a superconducting material such as ceramic, bismuth strontium calcium copper oxide (BSCCO), or yttrium barium copper oxide (YBCO). Additionally, in one embodiment, the resistor lead(s) 118 may be formed of copper, brass, phosphor bronze, or any combination of these materials.

[0063] Reference now Fig.11 , a flow chart showing an embodiment of a method 200 for energizing a plurality of superconducting coils of a superconducting magnet according to the present disclosure. Figures 1 to 10 The method 200 is described with reference to the superconducting magnet 10, superconducting circuit 16, and / or field charging system 100 described herein. However, one of ordinary skill in the art will appreciate that the disclosed method 200 may be used generally with any superconducting magnet having any suitable configuration. Fig.11 The steps specified in a particular order are depicted for purposes of illustration and discussion, but the methods discussed herein are not limited to any particular order or arrangement. Those skilled in the art using the disclosure provided herein will recognize that the various steps of the methods disclosed herein may be omitted, rearranged, combined and / or altered in various ways without departing from the scope of the present disclosure.

[0064] As shown at (202), method 200 includes coupling a field charging system to a plurality of superconducting coils and to at least one additional component of a superconducting magnet. Additionally, in one embodiment, the plurality of superconducting coils and the additional component are maintained at different temperatures. Additionally, as described herein, the field charging system has a power source, at least one HTS lead, and at least one flexible connector electrically coupled between the power source and the at least one HTS lead. Thus, as shown at (204), method 200 includes providing power to the field charging system via the power source to energize the plurality of superconducting coils. Thus, by energizing the plurality of superconducting coils in this manner, the (plurality) flexible connectors allow displacement and movement of components of the field charging system due to thermal expansion and contraction caused by different temperatures.

[0065] Various aspects and embodiments of the invention are defined by the following numbered clauses:

[0066] Clause 1. A superconducting circuit for a superconducting magnet, the superconducting circuit comprising:

[0067] a first temperature zone defining a first temperature;

[0068] a second temperature zone defining a second temperature, the second temperature being higher than the first temperature;

[0069] at least one first component positioned within a first temperature zone;

[0070] at least one second component positioned within the second temperature zone; and

[0071] A field charging system comprising:

[0072] at least one flexible connection electrically coupling the first member and the second member,

[0073] At least one of the flexible connections allows displacement and movement between the first component and the second component due to thermal expansion and contraction caused by different first and second temperatures.

[0074] Clause 2. The superconducting circuit of Clause 1, wherein the first member comprises a plurality of superconducting coils and the second member comprises at least one of a thermal shield surrounding the plurality of superconducting field coils, wherein the field charging system is configured to energize the plurality of superconducting coils.

[0075] Clause 3. The superconducting circuit of clause 2, wherein the field charging system further comprises a plurality of high current leads and a superconducting switch.

[0076] Item 4. A superconducting circuit according to Item 3, wherein the plurality of high current leads further include a pair of high temperature superconductor (HTS) leads and a pair of resistive leads, the pair of resistive leads being one or more power feedthroughs extending through the vacuum vessel and connected to the pair of HTS leads via at least one flexible connector, the pair of HTS leads being connected to a plurality of superconducting field coils and a superconducting switch.

[0077] Clause 5. A superconducting circuit according to clause 4, wherein the superconducting switch is mounted on a cold plate that is mechanically and thermally coupled to a support structure of the plurality of superconducting field coils, and

[0078] The pair of HTS leads are fixed on a cold plate.

[0079] Clause 6. The superconducting circuit of clauses 4-5, wherein the connection between the pair of HTS leads and the pair of resistive leads comprises at least one flexible connection and a thermal plate.

[0080] Clause 7. The superconducting circuit of clauses 4-6, wherein the pair of resistive leads comprises copper, brass, phosphor bronze, or a combination thereof.

[0081] Clause 8. The superconducting circuit of any of the preceding clauses, wherein the first temperature is less than about 10 Kelvin (K) and the second temperature is between about 35K and about 55K.

[0082] Clause 9. A superconducting circuit according to any of the preceding clauses, further comprising a third temperature zone defining a third temperature higher than the first temperature and the second temperature, wherein a third member is placed within the third temperature zone and connected to the second member via a second flexible connector of the at least one flexible connector.

[0083] Clause 10. The superconducting circuit of Clause 9, wherein the second component comprises a thermal shield in which the at least one electrical component is placed, and the third component comprises a vacuum vessel including the at least one electrical component placed therein.

[0084] Clause 11. A superconducting circuit according to any of the preceding clauses, wherein at least one flexible connection comprises a braided wire.

[0085] Clause 12. A field charging system for energizing a plurality of superconducting coils of a superconducting magnet, the field charging system comprising:

[0086] at least one high temperature superconductor (HTS) lead connecting a first temperature and a second temperature, the second temperature being different from the first temperature;

[0087] a power source at a different third temperature for providing power to the field charging system to energize the plurality of superconducting coils; and

[0088] at least one flexible connection electrically coupling at least one HTS lead at a first temperature and a power source at a second temperature;

[0089] At least one of the flexible connections allows displacement and movement of a component of the field charging system due to thermal expansion and contraction caused by the different first and second temperatures.

[0090] Clause 13. The field charging system of clause 12, wherein the power source comprises one or more power feedthroughs extending through the vacuum vessel and the thermal shield of the superconducting magnet.

[0091] Clause 14. The field charging system of clause 13, further comprising one or more rod components coupled to the one or more power feed-through lines at least partially within the heat shield.

[0092] Clause 15. A field charging system according to clause 14, wherein the at least one flexible connector includes at least one first flexible connector and at least one second flexible connector, the at least one first flexible connector is connected to one or more rod components and a first location on at least one hot plate, and the at least one second flexible connector is connected to a second location on at least one hot plate and at least one HTS lead.

[0093] Clause 16. The field charging system of clauses 12-15, further comprising a superconducting switch, the at least one HTS lead and the superconducting switch coupled to the plurality of superconducting coils.

[0094] Clause 17. A method for energizing a plurality of superconducting coils of a superconducting magnet, the method comprising:

[0095] coupling a field charging system to the plurality of superconducting coils and to at least one additional component of the superconducting magnet, the plurality of superconducting coils and the at least one additional component being maintained at different temperatures, the field charging system having a power source, at least one high temperature superconductor (HTS) lead, and at least one flexible connector electrically coupled between the power source and the at least one HTS lead; and

[0096] providing power to the field charging system via a power source to energize the plurality of superconducting coils,

[0097] At least one of the flexible connections allows for displacement and movement of components of the field charging system due to thermal expansion and contraction caused by different temperatures.

[0098] Clause 18. The method of Clause 17, wherein the power supply comprises one or more power feedthroughs extending through a vacuum vessel and a thermal shield of the superconducting magnet.

[0099] Clause 19. The method of clause 18, further comprising coupling the one or more pole members to one or more power feed-through lines.

[0100] Clause 20. The method of clause 19, wherein the at least one flexible connector comprises at least one first flexible connector and at least one second flexible connector, the method further comprising:

[0101] coupling at least one first flexible connector to the one or more rod members at a first location on at least one thermal plate; and

[0102] At least one second flexible connection is coupled to a second location on the at least one thermal plate and to the at least one HTS lead.

[0103] This written description uses examples to disclose the present disclosure, including the best mode, and also enables any person skilled in the art to practice the present disclosure, including making and using any device or system and performing any combined method. The patent scope of the present disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. If such other examples include structural elements that are not different from the written language of the claims, or if they include equivalent structural elements that are not substantially different from the written language of the claims, such other examples are expected to be within the scope of the claims.

Claims

1. A superconducting circuit for a superconducting magnet, the superconducting circuit comprising: a first temperature zone defining a first temperature; a second temperature zone defining a second temperature, the second temperature being higher than the first temperature; at least one first component positioned within the first temperature zone; at least one second component positioned within the second temperature zone; as well as A field charging system comprising: at least one flexible connector electrically coupling the first member and the second member, The at least one flexible connection allows displacement and movement between the first member and the second member due to thermal expansion and contraction caused by different first and second temperatures.

2. The superconducting circuit according to claim 1, characterized in that: The first component includes a plurality of superconducting coils, and the second component includes at least one of a thermal shield surrounding the plurality of superconducting field coils, wherein the field charging system is configured to energize the plurality of superconducting coils.

3. The superconducting circuit according to claim 2, characterized in that: The field charging system further includes a plurality of high current leads and a superconducting switch.

4. The superconducting circuit according to claim 3, characterized in that: The plurality of high current leads further include a pair of high temperature superconductor (HTS) leads and a pair of resistor leads, the pair of resistor leads being one or more power feedthroughs extending through the vacuum vessel and coupled to the pair of HTS leads via the at least one flexible connector, the pair of HTS leads being coupled to the plurality of superconducting field coils and the superconducting switch.

5. The superconducting circuit according to claim 4, characterized in that: The superconducting switch is mounted on a cold plate that is mechanically and thermally coupled to a support structure for the plurality of superconducting field coils, and The pair of HTS leads are fixed to the cold plate.

6. The superconducting circuit according to claim 4, characterized in that: The connection between the pair of HTS leads and the pair of resistor leads includes the at least one flexible connector and a thermal plate.

7. The superconducting circuit according to claim 4, characterized in that: The pair of resistor leads includes copper, brass, phosphor bronze, or a combination thereof.

8. The superconducting circuit according to claim 1, characterized in that: The first temperature is less than about 10 Kelvin (K), and the second temperature is between about 35K and about 55K.

9. The superconducting circuit according to claim 1, characterized in that: The superconducting circuit further includes a third temperature zone defining a third temperature higher than the first temperature and the second temperature, wherein a third member is placed within the third temperature zone and connected to the second member via a second flexible connector of the at least one flexible connector.

10. The superconducting circuit according to claim 9, characterized in that: The second component includes a heat shield having at least one electrical component disposed therein, and the third component includes a vacuum container including the at least one electrical component disposed therein.

11. The superconducting circuit according to claim 1, characterized in that: The at least one flexible connector includes a braided wire.

12. A field charging system for energizing a plurality of superconducting coils of a superconducting magnet, the field charging system comprising: at least one high temperature superconductor (HTS) lead connecting a first temperature and a second temperature, the second temperature being different from the first temperature; a power source at a different third temperature for providing power to the field charging system to energize the plurality of superconducting coils; as well as at least one flexible connection electrically coupling the at least one HTS lead at the first temperature and the power source at the second temperature; Wherein the at least one flexible connection allows displacement and movement of components of the field charging system due to thermal expansion and contraction caused by different first and second temperatures.

13. The field charging system according to claim 12, characterized in that: The power supply includes one or more power feedthroughs extending through the vacuum vessel and thermal shield of the superconducting magnet.

14. The field charging system according to claim 13, characterized in that: The electric field charging system further includes one or more rod components coupled to the one or more power feed-through lines at least partially within the heat shield.

15. The field charging system according to claim 14, characterized in that: The at least one flexible connector includes at least one first flexible connector and at least one second flexible connector, wherein the at least one first flexible connector is coupled to one or more rod components and a first location on at least one hot plate, and the at least one second flexible connector is coupled to a second location on the at least one hot plate and the at least one HTS lead.

16. The field charging system according to claim 12, characterized in that: The field charging system further includes a superconducting switch, the at least one HTS lead and the superconducting switch being coupled to the plurality of superconducting coils.

17. A method for energizing a plurality of superconducting coils of a superconducting magnet, the method comprising: coupling a field charging system to the plurality of superconducting coils and to at least one additional component of the superconducting magnet, the plurality of superconducting coils and the at least one additional component being maintained at different temperatures, the field charging system having a power source, at least one high temperature superconductor (HTS) lead, and at least one flexible connector electrically coupled between the power source and the at least one HTS lead; and providing power to the field charging system via the power source to energize the plurality of superconducting coils, Wherein the at least one flexible connection allows displacement and movement of components of the field charging system due to thermal expansion and contraction caused by the different temperatures.

18. The method according to claim 17, characterized in that The power supply includes one or more power feedthroughs extending through the vacuum vessel and thermal shield of the superconducting magnet.

19. The method according to claim 18, characterized in that The method further includes coupling one or more rod components to the one or more power feed-through lines.

20. The method according to claim 19, characterized in that The at least one flexible connector includes at least one first flexible connector and at least one second flexible connector, and the method further includes: coupling the at least one first flexible connector to the one or more rod members at a first location on the at least one thermal plate; and The at least one second flexible connection is coupled to a second location on the at least one thermal plate and to the at least one HTS lead.

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