Supplementary cooling system for superconducting electric machine

Abstract

A superconducting system, the superconducting system comprising: a superconducting motor, the superconducting motor comprising a superconducting magnet; a main cryogenic container containing a main refrigerant and surrounding the superconducting magnet; and a vacuum container surrounding the main cryogenic container. A supplemental cooling system is inside the vacuum vessel and includes a supplemental heat sink and an air gap thermal switch configured to alternately thermally connect the supplemental heat sink to and thermally isolate the supplemental heat sink from a component of the superconducting electric machine. The supplementary cooling system is configured to supplement cooling of the superconducting motor by the main cryogenic vessel to accelerate cooling of the components of the superconducting motor.

Description

Background Technology

[0001] This disclosure relates generally to superconducting motors, and more particularly to cooling systems for superconducting motors.

[0002] Superconducting motors utilizing superconducting magnets are known and used for a variety of purposes, including medical imaging and power generation. The superconducting magnet must be maintained at a cryogenic temperature and therefore within a sealed container providing vacuum conditions to minimize heat transfer from the outside. The cooling system, housed within the sealed vacuum container, is designed to transfer heat generated within the superconducting system to the outside. Therefore, such systems typically consist of a cryogenic container located within the vacuum container and traditionally rely on the endothermic properties of a liquid refrigerant (such as helium, hydrogen, or neon) coupled to a cryogenic cooler to cool the superconducting magnet and other components within the vacuum container.

[0003] Superconducting motors, including superconducting magnets, are utilized and configured for various purposes, including for magnetic resonance imaging and as superconducting generators (e.g., for wind turbines). These are non-limiting examples of superconducting motors that can be utilized in conjunction with the disclosed supplemental cooling system. The supplemental cooling system is thermally connected to at least one component of the superconducting motor and is configured to cool at least one component of the superconducting motor, which can be any part of the superconducting motor. For example, the supplemental cooling system can be used to cool components of the superconducting motor that intermittently generate large amounts of heat, such as portions of the superconducting motor that generate heat when conducting large amounts of current during certain sections of operation of the superconducting motor. To provide some examples, components of the superconducting motor can be superconducting switches and / or power ramp leads configured to cause the magnetic field generated by the superconducting magnet to ramp up and ramp down. The superconducting switch can be a magnet switch configured to power a magnet from a power supply and subsequently provide consistent magnet operation (such as for MRI and NMR), or the superconducting switch can be configured to intermittently connect to the power supply to allow trickle current to fill the magnetic field and ensure that the magnet can be rapidly and obliquely lowered as needed (such as for superconducting magnets in wind turbines).

[0004] Magnetic resonance (MR) systems used for magnetic resonance imaging (MRI) are an example of such superconducting machines. These systems produce images by subjecting objects with high hydrogen content, such as human tissue, to a uniform magnetic field (polarization field B0). This causes the individual magnetic moments of the spins in the tissue to attempt to align with the polarization field, but precess around it in a random order at their characteristic Larmor frequencies. If the material or tissue is subjected to a magnetic field (excitation field B1) that is in the xy-plane and close to the Larmor frequency, the net alignment torque, or "longitudinal magnetization," M... z It can be rotated or "tilted" into the xy plane to produce a net transverse magnetic moment M. tAfter the excitation signal B1 is terminated, a signal is emitted by the excited spin, and this signal can be received and processed to form an image.

[0005] MR systems can utilize superconducting magnets using NbTi conductors, and other superconductors can be employed at temperatures similar to or higher than NbTi. Furthermore, MR systems require a cooling system, which can be operated using a cryocooler (a very cold liquid). Ramp leads are used to energize the superconducting magnets used in MRI (and other types of superconducting machinery, such as motors and generators). Typically, these ramp leads can be fixed (permanently held in place) or detachable / retractable, and therefore have moving parts. Summary of the Invention

[0006] This summary is provided to introduce a series of concepts that will be further described in the detailed embodiments below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help limit the scope of the claimed subject matter.

[0007] In one aspect of this disclosure, a superconducting system includes: a superconducting motor including a superconducting magnet; a main cryogenic container containing a main cryogenic fluid and surrounding the superconducting magnet; and a vacuum container surrounding the main cryogenic container. A supplementary cooling system is located within the vacuum container and includes a supplementary heat sink and an air-gap thermal switch configured to alternately thermally connect the supplementary heat sink to a component of the superconducting motor and thermally isolate the supplementary heat sink from that component of the superconducting motor. The supplementary cooling system is configured to supplement the cooling of the superconducting motor by the main cryogenic container to accelerate the cooling of that component of the superconducting motor.

[0008] In one embodiment, the supplementary radiator is a refrigerant tank that includes a second refrigerant. Optionally, the second refrigerant may be a different refrigerant from the primary refrigerant. Optionally, the primary and second refrigerants each contain at least one of helium, hydrogen, neon, or nitrogen.

[0009] In another implementation, the supplementary radiator is a cryogenic cooler.

[0010] In another embodiment, the supplementary heat sink is at least part of the thermal shielding surrounding the superconducting magnet.

[0011] In another implementation, a supplemental radiator is thermally connected to the main cryogenic vessel to slowly dissipate heat to it.

[0012] In another aspect of this disclosure, a magnetic resonance imaging system includes: a superconducting motor including a superconducting magnet; a main cryogenic container containing a main cryogenic fluid and surrounding the superconducting magnet and configured to cool the superconducting magnet; and a vacuum container surrounding the main cryogenic container. A supplementary cooling system is located within the vacuum container and includes a supplementary heat sink and an air-gap thermal switch configured to alternately thermally connect the supplementary heat sink to components of the superconducting motor and thermally isolate the supplementary heat sink from the components of the superconducting motor. The supplementary cooling system is configured to supplement the cooling of the components of the superconducting motor by the cryogenic container to accelerate the cooling of the components of the superconducting motor.

[0013] In one embodiment, the supplemental cooling system includes at least: a first air gap thermal switch configured to thermally connect a supplemental radiator to a component; and a second air gap thermal switch configured to connect a component to a radiator different from the supplemental radiator.

[0014] In another embodiment, the superconducting motor includes a superconducting switch coupled to the superconducting motor and configured to switch between a resistive mode and a superconducting mode. An air-gap thermal switch is configured to thermally connect an auxiliary heatsink to the superconducting switch when the superconducting switch is in resistive mode, and to thermally isolate the auxiliary heatsink from the superconducting switch when the superconducting switch is in superconducting mode.

[0015] In another embodiment, the superconducting motor includes a power ramp lead disposed within a vacuum container and having a first end and a second end, wherein the first end of the power ramp lead is fixedly coupled to the vacuum container wall, and the second end is directly or indirectly coupled to a superconducting switch. An air gap thermal switch is configured to thermally connect an auxiliary heat sink to the power ramp lead when the superconducting switch is in resistive mode, and to thermally isolate the auxiliary heat sink from the power ramp lead when the superconducting switch is in superconducting mode.

[0016] In another aspect of this disclosure, a method for controlling a supplemental cooling system for a superconducting system includes: controlling a first air-gap thermal switch of a component connected to the superconducting system to thermally connect the component to a supplemental heat sink, and then, after the temperature of the component is below a first threshold temperature, controlling the first air-gap thermal switch to thermally isolate the component from the supplemental heat sink. Then, while the first air-gap thermal switch is thermally isolating the component from the supplemental heat sink, heat is slowly dissipated from the supplemental heat sink to the main heat sink over a period of time.

[0017] In one embodiment, after the component is cooled to a second threshold temperature via a supplementary heat sink, the method further includes controlling a second air-gap thermal switch of the component connected to the superconducting system to thermally connect the component to a heat sink different from the supplementary heat sink. After the component's temperature falls below a third threshold temperature, the second air-gap thermal switch is controlled to thermally isolate the component from the different heat sink.

[0018] In one implementation, the third threshold temperature is lower than the first threshold temperature and the second threshold temperature.

[0019] In one implementation, the first threshold temperature and the second threshold temperature are the same.

[0020] In another implementation, the first threshold temperature and the second threshold temperature are different.

[0021] In another implementation, the first threshold temperature is greater than the second threshold temperature.

[0022] In another embodiment, the component is a superconducting switch of a superconducting system.

[0023] In another embodiment, the component is the power ramp lead of the superconducting system.

[0024] In another embodiment, the superconducting system includes a magnet system for generating a magnetic field in a magnetic resonance imaging system.

[0025] Various other features, objects, and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings. Attached Figure Description

[0026] This disclosure is described with reference to the following figures.

[0027] Figure 1 This is a schematic diagram of an exemplary superconducting system including a superconducting magnet and a supplemental cooling system, according to some embodiments of the present disclosure.

[0028] Figure 2 This is a schematic diagram of an example magnetic resonance system based on various aspects of this disclosure.

[0029] Figure 3 This is a schematic cross-sectional view of an example magnetic resonance system having a power ramp lead coupled to a superconducting switch, according to various aspects of this disclosure.

[0030] Figure 4 This is a schematic diagram of a supplemental cooling system with an air gap thermal switch according to an embodiment of this disclosure.

[0031] Figure 5 This is a schematic diagram of another embodiment of the supplemental cooling system with an air gap thermal switch according to the embodiments of this disclosure;

[0032] Figures 6 to 9 Different embodiments of a supplemental cooling system configured as a cooling air gap thermal switch according to this disclosure are illustrated.

[0033] Figure 10 This is a flowchart illustrating one embodiment of a method for controlling the supplemental cooling system of this disclosure, wherein the supplemental cooling system includes two air gap thermal switches.

[0034] Figure 11 This is a schematic diagram illustrating an implementation scheme of a supplemental cooling system configured to cool a fixed ramp lead assembly. Detailed Implementation

[0035] In this description, certain terms are used for the purpose of brevity, clarity, and ease of understanding. No unnecessary limitations should be inferred from these terms beyond the requirements of the prior art, as they are used for descriptive purposes only and are intended to be understood in a broad sense.

[0036] As used herein, unless otherwise limited or restricted, discussions of specific orientations are provided by way of example only for particular embodiments or related illustrations. For instance, discussions of “top,” “bottom,” “front,” “back,” “left,” “right,” “horizontal,” “vertical,” and “longitudinal” features and / or relative movements (e.g., “upward” and “downward” movement) are generally intended only to describe the orientation of such features relative to a reference frame of a particular example or illustration. Accordingly, for example, in some arrangements or embodiments, a “top” feature may sometimes be positioned below a “bottom” feature (etc.). Alternatively or additionally, embodiments may be arranged with different orientations such that the “top” and “bottom” features are arranged horizontally relative to each other, for example, in a “left-to-right” orientation.

[0037] The terms “comprising,” “including,” or “having,” as used herein, and variations thereof, are intended to cover the elements listed thereafter and their equivalents, as well as any additional elements. An embodiment described as “comprising,” “including,” or “having” certain elements is also considered to be “substantially composed of those certain elements” and “composed of those certain elements.”

[0038] The disclosed cooling systems and methods are configured to provide supplemental cooling that increases the cooling capacity of the main cryogenic cooling system of the superconducting motor, enabling more rapid cooling of one or more of its components, particularly when said components are performing heat-generating activities to absorb and store heat. Superconducting motors including superconducting magnets have been utilized and configured for various purposes, including for magnetic resonance and as superconducting generators (e.g., for wind turbines). These are non-limiting examples of superconducting motors that can be utilized in conjunction with the disclosed supplemental cooling systems.

[0039] Thermal management is a challenge in all superconducting motors, including those with superconducting magnets that must be kept at or near the low end of a cryogenic temperature range below 120 K (-153 °C). During operation, components of the motor can generate heat that must be dissipated from the system. The main cryogenic cooling system may be insufficient to rapidly dissipate heat from all parts of the system and is typically configured to prioritize cooling the superconducting magnets. The inventors have recognized that this is particularly problematic for cryogenic superconducting motor systems where the heat absorption capacity of the main cryogenic cooling system cannot absorb all the heat generated by all components during peak operation and heat generation. Due to the decreasing availability of certain refrigerants, such as liquid helium, low-refrigerant-sealed superconducting motors with very limited refrigerant capacity (e.g., a few liters of helium) are becoming increasingly popular.

[0040] For example, changing the ramp of a superconducting magnet generates heat in the main ramp switch and ramp leads, which needs to be absorbed to keep the temperature under control. At the end of the ramp change, the switch and leads need to be cooled down to become superconducting. For the limited helium supply in the main cryogenic container of a hermetically sealed magnet system, the amount of heat may be too great to handle. Magnets with main ramp switches that include copper matrix superconductors are particularly vulnerable to damage.

[0041] Therefore, the inventors have recognized the need for a supplemental cooling system that can absorb heat during peak operation and slowly dissipate that heat during low operating times when the main cooling system has excessive capacity to dissipate heat. That is, the inventors have recognized the need for a cooling system that can be selectively used during peak heat generation times, preventing excessive heat from being transferred to the main cryogenic cooling system, thus avoiding the risk of overheating the superconducting magnet or other components. Therefore, the inventors have developed the disclosed supplemental cooling system, which provides an additional heat sink and is configured to store heat generated by one or more components of the superconducting motor during peak operating times (such as when the power ramp through the magnet rises), and slowly dissipate that heat through the main cooling system during lower operating times. For example, the supplemental heat sink may be a refrigerant tank containing a refrigerant (such as liquid helium, hydrogen, neon, or nitrogen), or it may be a cryogenic cooler. Alternatively, the supplemental heat sink may be a solid, such as a thermal shield (e.g., a thermal shield for an MRI magnet).

[0042] The inventors have further recognized that supplemental heat sinks need to be rapidly connected to the heat-generating component to absorb heat, and then disconnected from the heat-generating component once the high-heat task is completed and the component's temperature has sufficiently decreased, so that the stored heat is not immediately transferred back to the component, and therefore not back to the superconducting motor and system. Therefore, the inventors recognized that the component and heat sink must be separated by a switch, wherein the switch can thermally connect the component to the heat sink to achieve heat transfer to the heat sink, and thermally isolate or disconnect the component from the heat sink once cooling has occurred to prevent heat from the heat sink from being transferred back to the component, and thus back to the superconducting motor assembly.

[0043] The disclosed system includes at least one air-gap thermal switch configured to alternately connect a heat-generating component (such as a ramp switch or ramp lead) to a radiator and isolate the heat-generating component from the radiator, such as a refrigerant tank, a cryogenic cooler, or another solid within a vacuum vessel structure. The air-gap thermal switch enables efficient thermal connection and heat transfer from the heat source to the radiator to maintain temperature under control during peak operation. Once the heat transfer generated during peak operation is complete, the air-gap thermal switch opens to disconnect the radiator from the component. The air-gap thermal switch is configured to achieve sufficiently rapid and complete isolation between the heat-generating component and the radiator to prevent heat backflow into the component. The disclosed air-gap thermal switch operates well under vacuum conditions in a variety of superconducting motors and provides sufficiently fast connection and heat transfer to facilitate its use as a supplemental cooling system that can be switched on during peak heating operation of the component to absorb heat. Furthermore, the air-gap thermal switch and radiator arrangement is relatively small and can be mounted in any orientation, making it ideal for the limited space of superconducting systems such as MRI systems or wind turbines. The air gap thermal switch and radiator can be installed and operated in any orientation, which makes the disclosed system superior to other heat transfer devices such as thermosiphons and heat pipes.

[0044] In some implementations, multiple thermal switches and / or radiators may be used, such as each thermal switch and / or radiator being associated with one of a plurality of components, or multiple thermal switches being configured to cool a single component. Thus, multiple thermal switches can be used to connect a heated component to one or more radiators to accelerate the cooling process or to distribute heat across multiple radiators. Each air-gap thermal switch may be connected to its own different radiator, so the system may include multiple supplementary radiators. Alternatively, two or more air-gap thermal switches may be connected to a single, larger supplementary radiator. In the case where multiple air-gap switches are connected to a single component, they can each be configured to open and / or close at different temperatures, and thus manage different portions or temperature ranges of the cooling process. Several implementations of supplementary cooling systems are described herein, including examples of systems with multiple air-gap thermal switches configured to connect multiple radiators to a single component in a superconducting system and to isolate the multiple radiators from the single component in the superconducting system.

[0045] The disclosed supplemental cooling system, including an air-gap thermal switch and a radiator, enables the absorption and storage of most of the heat generated by the component, and thus reduces or eliminates the thermal melt between the component and the main cryogenic cooling system. This reduces the cooling load on the component / those components in the main cooling system, and therefore allows for a reduction in the capacity of the main cryogenic cooling system used to cool the superconducting magnet, and thus allows for the use of a smaller volume (and lighter weight) of refrigerant. For example, in the case where the component is a ramp switch and / or ramp lead assembly, the thermal melt between the ramp switch and / or ramp lead assembly and the main refrigerant container (e.g., a helium loop) can be made small (e.g., a narrow-diameter copper tube) so that the main cooling system absorbs only a portion of the heat generated by the ramp switch and / or ramp lead assembly during ramp changes.

[0046] A supplemental cooling system connects the ramp switch and / or ramp lead assembly to a supplemental radiator during ramp changes, the supplemental radiator being configured to transfer most of the heat generated during ramp changes to the supplemental radiator. For example, during the main ramp switch's closure, a gap thermal switch opens to disconnect the ramp switch from the supplemental radiator. In some embodiments, when the main ramp switch (or other component) is disconnected from the supplemental radiator, another thermal switch (such as a second gap thermal switch) closes to connect the main ramp switch to a main cryogenic cooling system, such as a liquid helium tank dispensing liquid helium to cool the superconducting magnet. This completes the cooling of the component using the main cooling system, but reduces the cooling load on the main cooling system, and thus allows for a reduction in the amount of refrigerant stored. In the case where the refrigerant is liquid helium, without the disclosed supplemental cooling system, the amount of helium can be readily reduced to less than 25% of the required original amount.

[0047] Figure 1 This is a schematic diagram illustrating a superconducting system 200 including at least one supplementary cooling system 100. The superconducting system 200 includes a superconducting motor 148 comprising a superconducting magnet 114, such as an MRI field-generating magnet system or a power generator (e.g., in a wind turbine). The superconducting motor 148 is contained within a vacuum container 19. A main cryogenic container 18 surrounds and is configured to cool the superconducting magnet 114. The cooling source (not shown) of the main cryogenic container 18 may be, for example, a cryocooler. The cooling effect of the cryocooler may be achieved using liquid helium and / or a high thermal conductivity solid (such as copper) distributed around the superconducting device within a tube. The main cryogenic container may include a thermal shield. A power ramp lead 52 is coupled to and provides electrical power to a superconducting switch 54, which, together with the power ramp lead, is configured to control the current to excite the magnet 114 to operate in a continuous current mode to generate a magnetic field. The superconducting switch 54 includes windings and is configured to switch between a resistive mode and a superconducting mode.

[0048] During the upward ramp of magnet 114, superconducting switch 54 is electrically connected to a power source in parallel with magnet 114. To generate a magnetic field, superconducting switch 54 operates in resistive mode, allowing current from the power source to be injected into the superconducting magnet coil. When the current flowing through the superconducting coil reaches the desired level for generating the magnetic field, superconducting switch 54 is switched to superconducting mode, and the external power source is disconnected. During the downward ramp of magnet 114, the magnetic field generated by superconducting magnet 114 is reduced by switching superconducting switch 54 back from superconducting mode to resistive mode. In resistive mode, current flowing through the resistor generates heat. The heat generated by superconducting switch 54 operating in resistive mode must be absorbed by a cooling system.

[0049] This switching is achieved by changing the temperature of the superconducting switch 54. In resistive mode, the superconducting switch 54 operates at a temperature above the superconducting temperature of the switch windings. In superconducting mode, the superconducting switch 54 operates at the superconducting temperature of the windings of the superconducting switch 54 (such as 4K). The superconducting switch 54 is cooled by a supplementary cooling system 100a, which is configured to absorb most of the heat generated by the superconducting switch 54 during the ramp-up of the magnet 114. The superconducting switch 54 is connected to the supplementary cooling system 100a via a thermal connector 199 or a thermal melt configured to transfer heat. The superconducting switch 54 may also be cooled by a main cryogenic container 18 to absorb the remainder of the heat that was not initially absorbed by the supplementary cooling system 100a. The main cryogenic container may also be used to finally cool the supplementary cooling system so that the superconducting switch slowly dissipates heat when operating in superconducting mode. A heater may be used to heat the superconducting switch 54 on demand to control the switching from superconducting mode to resistive mode.

[0050] The power ramp lead 52 can be a fixed ramp lead assembly or a removable ramp lead assembly. A supplemental cooling system 100b can be configured to cool the power ramp lead 52, particularly when the power ramp lead includes a fixed ramp lead assembly. In such embodiments, the power ramp lead 52 (or portions thereof) is connected to the supplemental cooling system 100b via a thermal connector 199 configured to transfer heat. The supplemental cooling system 100b configured to cool the power ramp lead 52 can be a supplement to a supplemental cooling system 100a configured to cool the superconducting switch, or the system 200 can include only one supplemental cooling system 100, which can be configured to cool either or both of the superconducting switch 54 or the power ramp lead 52. Therefore, the superconducting system 200 can include one or more supplemental cooling systems 100 (e.g., 100a and 100b). One or more supplemental cooling systems 100 can be configured to cool any or more of several different components of the superconducting system 200, such as... Figure 1 The example depicted shows the power ramp lead 52 and / or superconducting switch 54. Regardless of where the supplementary cooling systems 100a, 100b are configured to cool the component, the thermal connector 199 thermally connects the component to be cooled to the supplementary cooling system, which includes an air gap thermal switch and a radiator (see [link]). Figure 4 The supplementary cooling systems 100a and 100b can also be thermally connected to the main cryogenic vessel 18 via thermal connectors 199. For example, the thermal connector can be a copper strip or a heat pipe.

[0051] Figure 2 and Figure 3 An exemplary superconducting system is depicted as a magnet component 12 for an MR system 10. Figure 2 This is a schematic block diagram of an example MR system 10 for generating magnetic resonance images of a subject. In an example embodiment, the MR system 10 includes a magnet assembly 12, which includes a magnet 14. The magnet 14 is a superconducting magnet formed by a plurality of magnetic coils wound around a magnetic coil support or coil frame. The magnet 14 is configured to generate a polarizing magnetic field. As described in more detail below, the MR system 10 includes a current ramp lead assembly and a superconducting switch 54 configured to control the current passing through the superconducting magnet 14.

[0052] The magnet assembly 12 may include a main cryogenic container 18 surrounding the magnet 14, such as a cryostat container. The cryostat container 18 is typically filled with a cryogenic fluid or refrigerant used to cool the superconducting coil to extremely low temperatures (e.g., 4 Kelvin (K)) such that current continues to flow through the superconducting coil without resistance, to maintain a uniform and static magnetic field after the power supply is disconnected. The refrigerant may be helium, hydrogen, neon, nitrogen, or any combination thereof in liquid, gaseous, solid, or combined forms. Helium is described as an example refrigerant; however, any of the aforementioned refrigerants may be used. In some examples, the refrigerant may be hydrogen slurry (e.g., at 13 K), solid neon, or solid nitrogen.

[0053] refer to Figures 1 to 3 The magnet assembly 12 may also include a heat shield assembly 16 that encloses the main cryogenic container 18 and the magnet 14 therein. In one embodiment, the heat shield assembly 16 may include an inner heat shield member 162 and an outer heat shield member 164. The inner heat shield member 162 may typically be cylindrical in shape and radially positioned inside the magnet 14. The inner heat shield member 162 is configured to prevent heat from radiating from the warm area where the subject is placed to the cold area where the magnet 14 is placed. The outer heat shield member 164 is arranged concentrically relative to the inner heat shield member 162. Therefore, the outer heat shield member 164 may also be generally cylindrical in shape and radially positioned outside the magnet 14. The outer heat shield member 164 is configured to prevent heat from radiating from the environment into the magnet 14. The heat shield assembly 16 is made of a metallic material such as aluminum. In some embodiments, the magnet assembly 12 may also include a vacuum container 19 (e.g., having a vacuum container wall 21) that surrounds the heat shield assembly 16 and insulates the magnet 14 from the environment during operation.

[0054] In an example embodiment, the MR system 10 also includes a gradient coil assembly 22 disposed within an internal thermal shielding member 162. The gradient coil assembly 22 is configured to selectively apply one or more gradient magnetic fields along one or more axes such as the x-axis, y-axis, or z-axis. The MR system 10 also includes an RF coil 24. The RF coil 24 may be a transmitter coil configured to transmit RF pulses. The RF coil 24 may be a receiver coil configured to detect MR signals from a subject. The RF coil 24 may be a transmitting and receiving coil that both transmits and detects MR signals. The magnet assembly 12, the gradient coil assembly 22, and the main RF coil 24 are collectively referred to as the scanner assembly 50, as the scanner assembly 50 is formed as a unit and located within a scanner chamber. The scanner assembly 50 has an aperture 46 in which a subject is positioned during scanning. Figure 1The scanner assembly 50 shown is a closed aperture system, wherein the aperture is cylindrical. The scanner assembly 50 can be a magnet assembly with other designs, such as an open aperture system, a bipolar electromagnet configuration, or a Hallbach configuration.

[0055] In an example implementation, the MR system 10 also includes a controller 30, a magnetic field control 32, a gradient field control 34, a memory 36, a display device 38, a transmit / receive (T / R) switch 40, an RF transmitter 42, and a receiver 44. During operation, the subject is placed in an aperture 46 on a suitable support (e.g., a motorized operating table (not shown) or other patient worktable). A magnet 14 generates a uniform and static magnetic field B0 in the aperture 46. The strength and uniformity of the magnetic field B0 in the aperture 46 and correspondingly on the patient are controlled by the controller 30 via the magnetic field control 32, which also controls the supply of current to the magnet 14. A gradient coil assembly 22 is excited by the gradient field control 34 and also controlled by the controller 30, such that one or more gradient magnetic fields are applied to the magnetic field B0. The RF coil 24 and the receiving coil (if present) are selectively interconnected to either the RF transmitter 42 or the receiver 44 via the T / R switch 40, respectively. The RF transmitter 42 and the T / R switch 40 are controlled by the controller 30, such that RF field pulses or signals are generated by the RF transmitter 42 and selectively applied to the subject to excite magnetic resonance in the subject.

[0056] In an example implementation, after the RF pulse is applied, the T / R switch 40 is actuated again to decouple the RF transmit coil 24 from the RF transmitter 42. The detected MR signal is then transmitted to the controller 30, which is capable of organizing the MR signal in a specific format for storage in the memory 36. The controller 30 includes a processor 48 that controls the processing of the MR signal to generate a signal representing an image of the patient, which is transmitted to the display device 38 to provide a visual display of the image.

[0057] The superconducting magnet 14 of the magnet assembly 12 is used to generate a magnetic field in the MR system 10 by a current flowing along the magnet winding of the magnet 14. This current is in the range of several hundred amperes. In some known systems, a current from a power source is constantly applied to the magnet to generate the magnetic field. A constant supply of high current would significantly increase the operating cost of the MR system. The magnet 14 is a superconducting magnet, wherein the magnet 14 operates at a superconducting temperature (such as 4K) of the wire winding of the magnet 14, such that the winding wire has no resistance to current and no external power source is required. This operating mode of the magnet 14 is referred to as continuous current mode. Exemplary embodiments of the magnet assembly are shown and described in U.S. Patent Publication No. 2024 / 0136098.

[0058] The superconducting switch is located inside vacuum container 19. Figure 3 In the example shown, the superconducting switch 54 is located within the main cryogenic container 18. In other embodiments, the superconducting switch 54 may be located between the external thermal shield and the cryogenic container 18. Exemplary embodiments of the superconducting switch are disclosed in U.S. Patent Publication 2024 / 0136097.

[0059] Figure 3 An MR system 10 is depicted including a power ramp lead 52, which includes a fixed (or permanent) ramp lead assembly 56. In such embodiments, the fixed ramp lead assembly 56 may be disposed within a space 58 between the vacuum container wall 21 and the external heat shield 164 of the vacuum container 19. A portion of the fixed ramp assembly is located outside the vacuum container wall (at ambient temperature) and coupled to an external power supply 60. The current or power lead 52 also includes a high-temperature superconducting power lead 62 coupled to and supplying power to a superconducting switch 54. An exemplary embodiment of a power ramp lead including a fixed ramp lead assembly is shown and described in U.S. Patent Application No. 18 / 428,677.

[0060] See you again Figure 1 The superconducting system 200 (such as the magnet assembly 12 just described) includes at least one supplementary cooling system 100 and may include multiple supplementary cooling systems (e.g., 100a and 100b) configured to cool any or more of several different components of the superconducting system 200, such as... Figure 1 The power ramp lead 52 and / or superconducting switch 54 are shown. Figure 3 An embodiment including a supplementary cooling system 100 configured to cool the superconducting switch 54 is described.

[0061] Figure 4 This is a schematic diagram of an exemplary supplemental cooling system 100. The supplemental cooling system 100 includes an air-gap thermal switch 110 and a supplemental heat sink 180. The air-gap thermal switch is thermally connected to a component 99 of a superconducting system, such as the superconducting switch 54 and / or power ramp lead 52 shown and described above. The component 99 is thermally connected to the component side 115 of the air-gap thermal switch 110 via a thermal connector 199a. The air-gap thermal switch 110 is also connected to the heat sink 180, which has a heat sink side 156 connected to the supplemental heat sink 180 via a thermal connector 199b. For example, the thermal connector may be made of copper.

[0062] The air-gap thermal switch comprises two sets of fins: a component-side fin 117 on the component side 115 and a heat sink-side fin 157 on the heat sink side 156. The two sets of fins 157 are assembled together in a low-conductivity housing without contacting each other, resulting in an air gap 120 separating the fin sets 117 and 157. Fins 117 and 157 are formed of a thermally conductive material (such as copper) and are thermally connected to the component and heat sink, respectively. Specifically, the component-side fin 117 is connected to a heat-generating component 99, such as a superconducting switch 54 or a power ramp lead 52. The heat sink-side fin 157 is thermally connected to a supplementary heat sink 180, such as a refrigerant tank or a cryostat. Fins 117 and 157 are housed in a sealed housing 131, which provides a sealing condition and achieves a vacuum condition at low temperatures. For example, housing 131 may be constructed with very thin stainless steel walls.

[0063] An adsorption pump 130 is provided, configured to be fluidly connected to an air gap 120, and configured to thermally “open” and “close” a thermal switch 110 by adding gas molecules to and removing gas molecules from the air gap 120. The adsorption pump 130 includes an adsorbent material 134 or getter that, when cold (e.g., about 4K), absorbs and traps gas molecules to create a vacuum that thermally isolates fins 117 and 157 from each other. In this state, the thermal switch 110 is “open” and heat transfer between the fins is not permitted (or is minimized). When the adsorbent material is heated, it releases the absorbed gas into the air gap 120, which enables heat conduction between fins 117 and 157. In this heated state, the air gap thermal switch is “closed”, and heat is conducted from the warmer component-side fin 117 to the cooler radiator-side fin 157, which then conducts the heat to the radiator 180. For example, a radiator could be a refrigerant tank or a cryogenic cooler that starts at approximately 4K when the air gap thermal switch is closed.

[0064] The air gap 120 can contain any of a variety of suitable gases, and the amount of gas added to the air gap is calibrated to allow the air gap thermal switch 110 to open and close at the design temperature. The switching conductance when the switch is closed can be approximately several hundred or even several thousand W / m. 2 K. When gas is removed from the air gap 120, nothing transfers heat from one set of fins to another. In this case, the switching conductivity drops significantly, such as below 1 W / m. 2K. In this state where the air gap 120 is a vacuum, the air gap thermal switch is "on," and therefore minimal or no heat is conducted to the supplementary radiator 180. The supplementary radiator has a heat melt 199c to the main refrigerant container 18 to dissipate the stored heat over time. The heat melt 199c between the supplementary radiator 180 and the main refrigerant container 18 can be a relatively thin heat melt, so that heat dissipates relatively slowly into the main refrigerant, thus preventing the main cooling system from overheating.

[0065] Adsorbent material 134 is contained within housing 132. Adsorbent material 134 can be, for example, charcoal or other porous materials with a large surface area, such as zeolite, which allows for the capture of gas molecules upon cooling. Housing 132 of adsorption pump 130 is connected to air gap 120 via gas connector 124, which provides a channel 125 for transferring gas into and out of air gap 120 between fins 117 and 157. Housing 131, gas connector 124, and adsorption pump housing 132 contain calibrated amounts of gas. The gas quantity in the sealing system, the dimensions of adsorption pump housing 132, the amount of adsorbent material 134, and the length and diameter of gas channel 125 are configured such that air gap switch 110 can be turned on or "off" at a specified high temperature and turned off or "on" at a specified low temperature.

[0066] Heater 140 is configured to heat adsorption pump 130, causing adsorbent material 134 to release gas into air gap 120 to “close” the switch. Heater 140 can be a heater device controlled to heat adsorbent material to a predefined temperature. For example, heater 140 can be an electric heater that heats by flowing current through a resistor. In an exemplary embodiment, the heater can be in the form of a wire made of nicotrom nickel-chromium (i.e., a nickel and chromium alloy) or any other high-resistivity material, wrapped around the adsorption pump; or it can be in the form of a film heater attached to a surface, such as using glue or some form of adhesive. See now. Figure 5One embodiment is shown in which heater 140 can be controlled by controller 194, which is communicatively connected to temperature sensor 189. Controller 194 can be, for example, a microcontroller configured to receive sensed temperatures and control heater 140 based on the temperature of component 99 sensed by temperature sensor 189. Thus, controller 194 can be configured to turn on heater 140 when component 99 reaches a predetermined “on” temperature or a predetermined high threshold temperature. Depending on the configuration of adsorption pump 130, controller 194 can be configured to turn off heater 140 when component 99 reaches a predetermined cooling temperature or a low threshold temperature. Alternatively, controller 194 can be configured to operate heater 140 for a calibrated amount of time to heat adsorbent material 134. In other embodiments, heater 140 can also be operated based on input from a temperature sensor configured to sense the temperature of adsorbent material 134 to heat the adsorbent material to a predetermined temperature and maintain it at that temperature until air gap thermal switch 110 is opened to stop heat conduction by air gap thermal switch 110.

[0067] In other embodiments illustrated below, the heater may be thermally connected to component 99 or another heat source related to the temperature of the component, such that when the component heats up, the adsorbent material 134 is also heated, causing the air gap thermal switch 110 to close to transfer heat to the radiator 180. In such embodiments, the air gap thermal switch 110 may be configured to automatically open and / or close based on the temperature of component 99 thermally connected to adsorbent material 134, and therefore temperature sensing of the component is unnecessary and not performed.

[0068] Cooler 150 is configured to cool adsorption pump 130, causing adsorption material 134 to capture gas and remove it from air gap 120 to "turn on" the switch. Figure 5 As illustrated by example, cooler 150 may be a thermal connection to main refrigerant container 18, which in the case of MR system 10 may, for example, be liquid helium maintained at 4K. In such embodiments, cooler 150 may be configured to cool adsorbent material 134 to 4K and maintain it at that temperature when heater 140 is not in operation. Alternatively, cooler 150 may be connected to a cryogenic cooler or other cold head.

[0069] Figures 6 to 10 Examples illustrate various specific implementations, configurations, and control methods of the supplementary cooling system 100 configured as a cooling component, wherein the component is exemplarily a superconducting ramp switch 54a configured to act as a main ramp switch for changing the ramp of a superconducting magnet (such as an MRI magnet). Figure 6In the illustrated embodiment, the air-gap thermal switch 110a includes a supplementary heat sink 180a, which is a refrigerant tank, such as a liquid refrigerant (hydrogen, neon, nitrogen, helium, etc.). Alternatively, the refrigerant may be initially frozen, which can provide additional heat absorption capacity and further reduce the amount of refrigerant required to absorb the peak heat generated by the main slope superconducting switch 54a.

[0070] The air-gap thermal switch 110a has a component side 115 thermally connected to the main ramp superconducting switch 54a via a hot melt 199a and a radiator side 156 thermally connected to the supplementary radiator 180a via a hot melt 199b. The supplementary radiator 180a is connected to the main refrigerant container 18 via a hot melt 199c, which is a narrower or more restrictive melt than hot melts 199a and 199b, and is therefore configured to slowly dissipate heat into the main refrigerant circuit. The hot melt 199d between the superconducting ramp switch 54a and the main refrigerant container 18 also performs restricted heat transfer, transferring heat much more slowly than the heat transfer via the thermal connections 199a and 199b of the air-gap thermal switch 110a. For example, the hot melt 199d could be a narrow copper strip, sized to transfer a predetermined small amount of heat. Therefore, during ramp changes, when the air-gap thermal switch 110a opens and transfers heat, most of the heat generated during ramp changes due to current flowing through the switch is transferred to the heat sink 180a via the thermal switch 110a because it has a much higher conductivity than that possible through the thermal melt 199d. For example, tens or even hundreds of watts can be transferred through the air-gap thermal switch 110a, while the thermal melt can be configured to transfer only a portion of that energy, such as less than 1 watt (e.g., 10W is transferred through the air-gap thermal switch 110a when it is transferring heat, while only 0.5W is transferred through the thermal melt 199d).

[0071] The transfer through the air-gap thermal switch 110a is controlled based on the temperature of the adsorbent material 134. The adsorption pump 130 is connected to the main cryogenic vessel 18 via a heat melt 150a, which provides a cooler for the adsorbent material 134, thus continuously cooling the adsorbent material. A heating mechanism is configured to add heat to the adsorbent material 134 when the air-gap thermal switch 110a is to be opened, thereby adding gas to the air gap of the thermal switch 110a through gas passage 125. Heating can be performed, for example, by a heater 140, and controlled by a controller 194 based on the sensed temperature of a component (here, the superconducting ramp switch 54a) (and in some embodiments, the temperature of a supplementary heat sink 180a and / or the temperature of the adsorbent material 134), as described above. Figure 5 As described.

[0072] Alternatively, the heater may be a thermal connection to the component, which in this case is a superconducting ramp switch 54a. Figure 7 An example of such an embodiment is illustrated, in which the adsorption pump 130 is heated via a thermal connection 140a to the superconducting ramp switch 54a. Therefore, when the superconducting ramp switch 54a heats up, the adsorbent material 134 also heats up, thereby opening the air gap thermal switch 110a'. In this embodiment, the air gap thermal switch 110a' is automatically heated when the component is heated, and the thermal connection 140a can be designed so that no additional heating is required. For example, the thermal fusion element 140a can be a copper connector or wire configured to transfer sufficient heat such that when the superconducting ramp switch 54a reaches a predetermined temperature (such as 10K, 15K, or some value closer to 25K, or even higher, possibly in the range of 80K (which could be the maximum design temperature of the ramp switch 54a)), the air gap thermal switch 110a' opens. In such implementations, no thermal sensor or heater controller is required because the air gap thermal switch 110a′ is naturally and mechanically controlled via the activity of thermal connectors 140a and 150a and ramp switch 54a.

[0073] Therefore, in Figure 7 and Figure 8 In the illustrated embodiment, the adsorbent material 134 is continuously cooled via a cooler 150a, which is a thermal connection to the main refrigerant circuit. Heat is then added to close the air gap thermal switch 110a and initiate heat conduction. Once the heat is turned off or no further significant heat is added to keep the adsorbent material 134 warm, the adsorbent material 134 will cool back to the temperature of the main refrigerant, such as 4K, and the switch will be turned on, making it no longer a conductor of heat.

[0074] Alternatively, in other embodiments, the adsorbent material 134 can be thermally bonded to the component (here, the superconducting ramp switch 54a), such that the air gap thermal switch 110 closes when the component becomes hot and opens once the component is sufficiently cool. In such embodiments, instead of separate heaters and coolers, only a single thermal connection to the adsorption pump may exist, where both heating and cooling originate from the thermal connection to the component. Relative to Figure 11 An example of such an implementation is shown and described.

[0075] Figure 8 Another embodiment of the air-gap thermal switch 110a″ configured to cool the superconducting ramp switch 54a is depicted, wherein in the depicted embodiment, the supplementary heat sink 180b is a cryogenic cooler. For example, the supplementary heat sink 180b may be a single-stage cryogenic cooler. In one specific embodiment, the cryogenic cooler 180b may be contained in a secondary vacuum jacket, which allows for cooling without damaging the vacuum container 19 (see...). Figures 2 to 3The cryogenic cooler can be installed and removed without interfering with the operation of the magnets, while maintaining the main vacuum. In other embodiments, the supplementary heat sink can be solid, such as a thermally connected component to a portion of the thermal shielding assembly 16 (see [link to other embodiments]). Figure 2 ).

[0076] Figure 9 Another specific embodiment in which a second air-gap thermal switch 110e is added is illustrated. Thus, two air-gap thermal switches 110a and 110e are connected to a component, such as a superconducting ramp switch 54a, to accelerate the cooling process. In some embodiments, the two air-gap thermal switches 110a and 110e can be configured to open or conduct heat at different temperatures, and thus handle different hot sections of the cooling process. The first air-gap thermal switch 110a is configured to connect the superconducting ramp switch 54a to and disconnect the supplementary heat sink 180a, and can have the above-mentioned characteristics relative to... Figures 6 to 8 Any of the various configurations described. The first adsorption pump 130a can be heated by an active heater 140, which is controlled by a controller 194 in response to a sensed temperature, such as... Figure 5 As shown and described. Alternatively, the first adsorption pump 130a can be passively controlled and heated via a thermal connection with the superconducting ramp switch 54a, such as... Figure 7 As shown.

[0077] The second air-gap thermal switch 110e connects the superconducting ramp switch 54a to the second heat sink, which can be as follows: Figure 9 The main cryogenic container 18 shown may be a second supplementary radiator (not shown). The second air-gap thermal switch 110e has a component side 115e thermally connected to component 54a and a radiator side 156e connected to the radiator, which here is the main cryogenic container 18. The adsorption pump 130e is configured to turn the second thermal switch 110e on and off when the adsorbent material therein is heated and cooled, respectively. The adsorbent material in the adsorption pump 130e may be, for example, charcoal or other materials as described above. The adsorption pump 130e is cooled by a cooler 150e, which is a hot melt to the main refrigerant. The adsorption pump 130e is heated by a heater 140e. The heater 140e may be an active heater controlled by a controller (not shown) based on the temperature sensed by the component (e.g., by a temperature sensor 189a configured to sense the temperature of the superconducting ramp switch 54a).

[0078] The first air gap thermal switch 110a and the second air gap thermal switch 110e can be configured to open and close at different temperatures, and thus at different times during the cooling process of the superconducting ramp switch 54a. Figure 10An embodiment of a cooling process and method 1000 for controlling the cooling of a component is shown, wherein a supplemental cooling system includes two air gap thermal switches attached to the component and configured to facilitate cooling, which will refer to Figure 9 The implementation scheme is explained below. At step 1022, the superconducting ramp switch 54a is operated to cause the magnet ramp to rise. For example, all components can be completely cooled to an initial temperature equal to the temperature of the main cryogenic container, such as 4K. The superconducting ramp switch 54a will rapidly begin to heat up. At step 1004, the first heater (not shown) of the first air gap thermal switch 110a is operated to heat the adsorption pump 130a, thereby shutting off the first air gap thermal switch 110a. For example, the heater can be actively controlled by a controller, or it can be a passive heater thermally connected to the ramp switch 54a. The first air gap thermal switch 110a remains closed (i.e., the heater continues to heat the adsorbed material of the first thermal switch 110a), and thus conducts heat to the supplementary radiator 180a until after the ramp change is completed at step 1006, and until the ramp switch 54a cools to a first threshold temperature at step 1008. For example, if the initial cold temperature before the ramp change is 4K, the first threshold temperature can be 20K.

[0079] Once the ramp switch 54a falls below the first temperature, the first air gap thermal switch 110a is shut off at step 1010, for example, by turning off the first heater. At step 1012, the second air gap thermal switch 110e is turned off or on by controlling the second heater 140e to heat the adsorption pump 130e. The second air gap thermal switch 110e remains off, for example, by continuing to heat the adsorption pump 130e, until the ramp switch 54a reaches the second threshold temperature at step 1014. For example, if the initial cold temperature before the ramp change is 4K and the first temperature threshold is 20K, the second temperature threshold could be 6K. Once the second temperature threshold is reached, the second heater 140e is turned off at step 1016, thereby turning on the second air gap thermal switch 110e so that it no longer transfers heat. The ramp switch 54a will continue to cool slowly via the hot melt 199d through heat transfer to the main cryogenic container 18, which is a narrow (or “weak” hot melt as described above. The supplementary radiator 180a will also slowly dissipate heat to the main cryogenic container 18 via the heat melt 199c until it is cooled to the same temperature as the main refrigerant, or until the ramp change begins again, whichever happens first. The heat melts 199c and 199d are configured to be narrow or “weak” enough that not much heat is transferred to the main refrigerant at any given time, thus preventing overloading of the main cooling circuit.

[0080] Figure 11An embodiment is shown in which the air gap thermal switch 110f is configured to alternately connect and disconnect the power ramp lead 52, which is here a fixed ramp lead assembly 56. As described above, the fixed ramp lead assembly 56 can be positioned within the vacuum container wall 21 (and thus inside the vacuum container) and is used to excite the magnet (e.g., above). Figure 1 and Figure 2 The temperature of the conductive disk 221 increases during energization and needs to be cooled. The fixed ramp lead assembly 56 includes a series of conductive disks 221, such as those made of highly conductive copper, separated by partitions 222 of a material with lower thermal conductivity (such as brass). The air gap thermal switch 110f is configured to close during energization to transfer heat from the fixed ramp lead assembly 55 to the heat sink 180f to cool the fixed ramp lead assembly 56. The component end 115f of the air gap thermal switch is thermally connected to a portion of the fixed ramp lead assembly 56 so as to the partition 222. The heat sink side 156f of the thermal switch 110f is thermally connected to the supplementary heat sink 180f, such as a supplementary refrigerant tank or a cryogenic cooler. Alternatively, the supplementary heat sink 180f may be a thermal shielding assembly 16 (see [link to documentation]). Figures 2 to 3 The supplementary radiator 180f is configured to slowly transfer heat via the thermal melt 199c to another, possibly larger, radiator, such as to a cold head configured to cool the main cryogenic container.

[0081] In the depicted embodiment, the temperature of the adsorption pump, and therefore the opening and closing operation of the thermal switch 110f, can be passively controlled via a thermal melt 199z that correlates the temperature of the adsorbed material in the adsorption pump 130f with the temperature of a portion of the component, here the conductive disk 221 of the fixed ramp lead assembly 56. Thus, when the conductive disk 221 of the fixed ramp lead assembly 56 is heated, the air gap thermal switch 110f closes to allow heat transfer to the supplementary radiator 180g. Once the conductive disk 221 of the fixed ramp lead assembly 56 has cooled, the adsorption pump 130f will also cool, which will open the air gap thermal switch 110f, preventing further significant heat transfer between the supplementary radiator 180f and the fixed ramp lead assembly 56. Figure 11 This thermal control arrangement relative to the fixed ramp lead assembly 56 is illustrated. Similar arrangements can be used with the superconducting switch 54 or other components.

[0082] Alternatively, the adsorption pump 130f can be connected to a separate cooler and can be heated via a connection to the fixed ramp lead assembly. In other embodiments, the temperature of the adsorption pump 130f can be actively heated by a heater controlled based on the sensed temperature of the fixed ramp lead assembly 56.

[0083] In some embodiments, any suitable computer-readable medium may be used to store instructions for performing the functions and / or processes described herein, such as instructions executed by a controller. For example, in some embodiments, the computer-readable medium may be transient or non-transient. For example, a non-transient computer-readable medium may include media such as magnetic media (such as hard disks, floppy disks, etc.), optical media (such as compact discs, digital video discs, Blu-ray discs, etc.), semiconductor media (such as RAM, flash memory, electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.), any suitable medium that does not appear transiently or without any persistent appearance during transmission, and / or any suitable tangible medium. As another example, a transient computer-readable medium may include signals on a network, in wires, conductors, optical fibers, circuits, or in any suitable medium that appears transiently and lacks any persistent appearance during transmission, and / or any suitable intangible medium.

[0084] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to perform and use the invention. Certain terms are used for the purposes of brevity, clarity, and ease of understanding. Unnecessary limitations should not be inferred from this description beyond the requirements of the prior art, as such terms are used for descriptive purposes only and are intended to be understood broadly. The patent scope of this invention is defined by the claims and may include other examples that would occur to a person skilled in the art. These other examples are intended to be within the scope of the claims if they have features or structural elements that are not different from the literal language of the claims, or if they include equivalent features or structural elements that are not substantially different from the literal language of the claims.

Claims

1. A superconducting system, the superconducting system comprising: Superconducting motor, the superconducting motor including a superconducting magnet; A main cryogenic container, the main cryogenic container containing a main cryogenic fluid and surrounding the superconducting magnet; A vacuum container that surrounds the main cryogenic container; A supplemental cooling system, the supplemental cooling system being located inside the vacuum container and comprising: Add a heat sink; An air-gap thermal switch configured to alternately thermally connect the supplementary heat sink to components of the superconducting motor and thermally isolate the supplementary heat sink from the components of the superconducting motor; and The supplemental cooling system is configured to supplement the cooling of the superconducting motor by the main cryogenic vessel, thereby accelerating the cooling of the components of the superconducting motor.

2. The system of claim 1, wherein the supplementary radiator is a refrigerant tank comprising a second refrigerant.

3. The system of claim 2, wherein the refrigerant tank is thermally connected to the main cryogenic container to dissipate heat therefrom.

4. The system of claim 2, wherein the second refrigerant is different from the main refrigerant.

5. The system of claim 2, wherein the primary refrigerant and the second refrigerant each comprise at least one of helium, hydrogen, neon, or nitrogen.

6. The system of claim 1, wherein the supplementary heat sink is a cryogenic cooler.

7. The system of claim 1, wherein the supplementary heat sink is at least a portion of the thermal shield surrounding the superconducting magnet.

8. The system of claim 1, wherein the superconducting motor is a magnet system for a magnetic resonance imaging machine or a power generator, and wherein the components of the superconducting motor include at least one of a superconducting switch and a power ramp lead.

9. A magnetic resonance imaging system comprising a superconducting system according to any one of claims 1 to 7.

10. The system of claim 9, wherein the supplemental cooling system comprises at least: A first air gap thermal switch is configured to thermally connect the supplementary heat sink to the component. A second air gap thermal switch, configured to connect the component to a heat sink different from the supplementary heat sink.

11. The system of claim 9, wherein the superconducting motor includes a superconducting switch coupled to the superconducting motor and configured to switch between a resistive mode and a superconducting mode; The air gap thermal switch is configured to thermally connect the supplementary heat sink to the superconducting switch when the superconducting switch is in the resistive mode, and to thermally isolate the supplementary heat sink from the superconducting switch when the superconducting switch is in the superconducting mode.

12. The system of claim 9, wherein the superconducting motor includes a power ramp lead disposed within the vacuum container and having a first end and a second end, wherein the first end of the power ramp lead is fixedly coupled to the vacuum container wall of the vacuum container, and the second end is directly or indirectly coupled to a superconducting switch; and The air gap thermal switch is configured to thermally connect the supplementary heat sink to the power ramp lead when the superconducting switch is in resistive mode, and to thermally isolate the supplementary heat sink from the power ramp lead when the superconducting switch is in superconducting mode.

13. A method for controlling a supplemental cooling system for a superconducting system, the method comprising: The first air gap thermal switch controlling the component connected to the superconducting system thermally connects the component to a supplementary heat sink. After the temperature of the component is lower than the first threshold temperature, the first air gap thermal switch is controlled to thermally isolate the component from the supplementary heat sink. as well as While the first air gap thermal switch is thermally isolating the component from the supplementary heat sink, heat is slowly dissipated from the supplementary heat sink to the main heat sink over a period of time.

14. The method according to claim 13, further comprising: After the component is cooled to the second threshold temperature via the supplementary heat sink, the second air gap thermal switch of the component connected to the superconducting system is controlled to thermally connect the component to a heat sink different from the supplementary heat sink. After the temperature of the component is lower than the third threshold temperature, the second air gap thermal switch is controlled to thermally isolate the component from the different heat sinks; and The third threshold temperature is lower than the first threshold temperature and the second threshold temperature.

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