Superconducting magnet and magnetic resonance imaging device

Abstract

A superconducting magnet, comprising a superconducting coil and a refrigeration mechanism. The superconducting coil comprises a coil main body and a heat exchanger tube, the heat exchanger tube being mounted on the coil main body and configured to exchange heat with the coil main body. The refrigeration mechanism comprises a low-temperature refrigerating device and a gas storage tank, the gas storage tank being communicated with the heat exchanger tube.

Description

Superconducting magnets and magnetic resonance imaging equipment

[0001] This application claims priority to the Chinese patent application with application number 202311536707.X filed with the China Patent Office on November 15, 2023, entitled “Superconducting Magnet and Magnetic Resonance Imaging Equipment,” the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention belongs to the technical field related to superconducting coil cooling, and in particular relates to a superconducting magnet and a magnetic resonance imaging device. Background Art

[0003] The superconducting coil is the core component of the superconducting magnet. The superconducting coil requires a helium gas-liquid two-phase system as a heat transfer medium to stabilize the temperature of the superconducting coil at 4.2 Kelvin under 1 atmosphere of pressure to achieve a superconducting state. In this way, the superconducting coil can generate a highly stable and high-field-strength magnetic field when working to meet the requirements of magnetic resonance scanning.

[0004] Currently, existing superconducting magnets typically immerse the superconducting coil in liquid helium, utilizing heat exchange between the liquid helium and the superconducting coil to stabilize the temperature of the superconducting coil at 4.2 Kelvin and achieve a superconducting state. To this end, the superconducting magnet requires a liquid helium tank to hold the liquid helium, and a large amount of liquid helium is injected into the tank to control the ambient temperature of the superconducting coil so that the superconducting coil can generate a highly stable, high-field-strength magnetic field when in operation. However, in order to meet the requirement of immersing the superconducting coil in liquid helium, the superconducting magnet typically requires hundreds to thousands of liters of liquid helium. Liquid helium, as a non-renewable scarce resource, is relatively expensive, resulting in high overall production costs for superconducting magnets.

[0005] Summary of the Invention

[0006] On one hand, the present application provides a superconducting magnet, comprising:

[0007] A superconducting coil, comprising a coil body and a heat exchange tube, wherein the heat exchange tube is mounted on the coil body and configured to perform heat exchange with the coil body;

[0008] The refrigeration mechanism includes a low-temperature refrigerator and a gas storage tank, and the gas storage tank is connected to the heat exchange pipe.

[0009] In some embodiments, the refrigeration mechanism includes a phase separator, which is respectively connected and communicated with the gas storage tank and the heat exchange tube, so that the gas storage tank is communicated with the heat exchange tube through the phase separator. The low-temperature refrigerator has a secondary cold head, and the phase separator is installed on the secondary cold head and is configured to perform heat exchange with the secondary cold head.

[0010] In some embodiments, the superconducting magnet further includes a room temperature outer container, wherein a vacuum cavity is formed inwardly of the room temperature outer container, and the phase separator and the superconducting coil are both accommodated in the vacuum cavity.

[0011] In some embodiments, the cryogenic refrigerator further comprises a primary cold head, and the gas storage tank is mounted on the primary cold head and configured to perform heat exchange with the primary cold head.

[0012] In some embodiments, the primary cold head is configured to cool the helium in the gas storage tank, and the secondary cold head is configured to liquefy the helium entering the phase separator after being cooled by the primary cold head. In some embodiments, the primary cold head is configured to provide a first cooling power within a first temperature range, and the secondary cold head is configured to provide a second cooling power within a second temperature range, wherein the first cooling power is greater than the second cooling power, and the first temperature range is higher than the second temperature range.

[0013] In some embodiments, the first temperature range is from 30 Kelvin to 300 Kelvin.

[0014] In some embodiments, the superconducting magnet further includes an external refrigerator, which is connected to and communicates with the gas storage tank and is configured to perform heat exchange with the gas storage tank.

[0015] In some embodiments, a gas valve is installed on the passage connecting the external refrigerator and the gas storage tank, and the gas valve is configured to control the on / off of the passage.

[0016] In some embodiments, the superconducting magnet further includes a cold shield disposed at the periphery of the superconducting coil and configured to perform heat exchange with the gas storage tank.

[0017] In some embodiments, heat exchange is performed between the cold screen and the gas storage tank via a flexible connecting belt.

[0018] In some embodiments, the superconducting magnet further includes a pipe located outside the cold shield, and both ends of the pipe are respectively connected to the gas storage tank.

[0019] In some embodiments, at least one additional gas storage tank connected to the pipeline is provided on the pipeline, and the additional gas storage tank is configured to perform heat exchange with the cold screen.

[0020] In some embodiments, the gas storage tank is connected to and communicated with an air inlet pipe for introducing refrigerant into the gas storage tank and an air outlet pipe for draining the refrigerant.

[0021] In some embodiments, the cryogen comprises liquid nitrogen.

[0022] In some embodiments, the superconducting magnet further includes a detection mechanism configured to monitor the liquid nitrogen discharged from the gas outlet pipe.

[0023] In some embodiments, the gas storage tank is configured to discharge liquid nitrogen stored therein from the gas outlet pipe when helium gas is input from the gas inlet pipe.

[0024] In some embodiments, the superconducting magnet further comprises a room temperature outer container, wherein a vacuum chamber is formed inwardly of the room temperature outer container, and the gas storage tank is accommodated in the vacuum chamber.

[0025] In some embodiments, the primary cold head is installed inside the gas storage tank, and / or the secondary cold head is installed inside the phase separator.

[0026] Another aspect of the present application provides a magnetic resonance imaging device, comprising the superconducting magnet according to any one of the above embodiments.

[0027] The details of various embodiments of the present invention will be described in the following drawings and descriptions. According to the description, drawings and claims, those skilled in the art will easily understand other features, problems solved and beneficial effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] FIG1 is a schematic structural diagram of a superconducting magnet provided in one embodiment of the present application;

[0030] FIG2 is a schematic structural diagram of a superconducting magnet provided in one embodiment of the present application, wherein a gas storage tank is connected to and communicated with an external refrigerator;

[0031] FIG3 is a schematic diagram of the structure of a superconducting magnet provided in one embodiment of the present application, wherein the gas storage tank can first be introduced with liquid nitrogen through an inlet pipe;

[0032] FIG4 is a schematic structural diagram of a superconducting magnet provided in another embodiment of the present application;

[0033] FIG5 is a schematic structural diagram of a superconducting magnet provided in another embodiment of the present application. DETAILED DESCRIPTION

[0034] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] It should be noted that when an element is referred to as being “provided on” another element, it may be directly provided on the other element or there may be an intermediate element. When an element is considered to be “provided on” another element, it may be directly provided on the other element or there may be an intermediate element. When an element is considered to be “fixed to” another element, it may be directly fixed to the other element or there may be an intermediate element.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] As shown in Figures 1 to 5, the superconducting magnet 100 provided in some embodiments of the present application includes a superconducting coil 10 and a refrigeration mechanism 20. The superconducting coil 10 includes a coil body 11 and a heat exchange tube 12. The heat exchange tube 12 is installed on the coil body 11 and can exchange heat with the coil body 11; the refrigeration mechanism 20 includes a low-temperature refrigerator 22 and a gas storage tank 23. The gas storage tank 23 is connected to the heat exchange tube 12, so that the cooling gas or liquid in the gas storage tank 23 can enter the heat exchange tube 12, thereby exchanging heat with the coil body 11.

[0038] In some embodiments, the refrigeration mechanism 20 includes a phase separator 21, which is connected to and communicates with the gas storage tank 23 and the heat exchange tube 12, respectively, so that the gas storage tank 23 is connected to the heat exchange tube 12 through the phase separator 22. The phase separator 21 is configured to allow helium to enter for liquefaction and to provide liquid helium to the heat exchange tube 12. The cryogenic refrigerator 22 has a secondary cold head 221, on which the phase separator 21 is mounted and capable of heat exchange with the secondary cold head 221. For example, the phase separator 21 can be mounted to the secondary cold head 221 by welding. As shown in Figures 1-3, in some embodiments, the secondary cold head 221 is mounted to the interior of the phase separator 21. It will be appreciated that in other embodiments, the secondary cold head 221 is mounted to the surface of the phase separator 21. The secondary cold head 221 is capable of cooling the helium medium within the phase separator 21, causing the helium medium to liquefy and flow into the heat exchange tube 12. That is, the superconducting magnet 100 of the present application uses heat exchange between the heat exchange tube 12 through which liquid helium is conducted and the coil body 11 to reduce the temperature of the coil body 11, so that the superconducting coil 10 reaches a superconducting state. It should be noted that the above-mentioned secondary cold head 221 cools the helium medium in the phase separator 21 so that the helium medium is liquefied and flows into the heat exchange tube 12. Specifically, the secondary cold head 221 of the low-temperature refrigerator 22 can liquefy the gaseous helium in the phase separator 21 into liquid helium. At the same time, the secondary cold head 221 can also cool the liquid helium in the phase separator 21. That is, the above-mentioned helium medium can specifically include helium gas and helium liquid, wherein the helium gas can be liquefied into liquid helium through the cooling of the phase separator 21 by the secondary cold head 221.

[0039] It can be understood that the superconducting coil 10 reaches a superconducting state by utilizing heat exchange between the heat exchange tube 12 through which helium liquid is conducted and the coil body 11 . This can reduce the amount of liquid helium used in the superconducting magnet 100 , thereby saving liquid helium resources and reducing the overall production cost of the superconducting magnet 100 .

[0040] It should be noted that the heat exchange tube 12 in the superconducting coil 10 of the present application is arranged to match the coil body 11, and in order to improve the heat exchange efficiency during heat conduction between the heat exchange tube 12 and the coil body 11, multiple heat exchange fins can be arranged on the heat exchange tube 12, and the multiple heat exchange fins are respectively in contact with the coil body 11 to increase the contact area between the heat exchange tube 12 and the coil body 11 during heat exchange. The specific arrangement of the heat exchange tube 12 on the coil body 11 can be specifically set according to the use requirements of the heat exchange between the heat exchange tube 12 and the coil body 11. For example, in some embodiments, the heat exchange tube 12 is arranged inside the coil body 11, for example, in a spiral shape. In other embodiments, the heat exchange tube 12 can be sleeved on the outside of the coil body 11. As shown in Figures 1 to 3, in some embodiments, the refrigeration mechanism 20 also includes a gas storage tank 23, which is connected to and communicates with the phase separator 21; wherein the gas storage tank 23 can store helium. When the refrigeration mechanism 20 is operating, the gas tank 23 can be used to supply helium to the phase separator 21, so that the low-temperature refrigerator 22 can liquefy the helium by cooling the phase separator 21 through the secondary cold head 221, so that liquid helium can be conducted between the phase separator 21 and the heat exchange tube 12. The gas tank 23 can be configured to accommodate the helium gas after the liquid helium in the phase separator 21 is vaporized. For example, the gas tank 23 can completely accommodate the helium gas after the liquid helium in the phase separator 21 is vaporized. In some embodiments, the gas tank 23 and the phase separator 21 can both be configured as a tank structure.

[0041] As shown in Figures 1 to 3 , in some embodiments, the cryogenic refrigerator 22 further includes a primary cold head 222 , which is mounted on the gas tank 23 and capable of exchanging heat with the gas tank 23. For example, the gas tank 23 can be mounted to the primary cold head 222 by welding. As shown in Figures 1-3 , in some embodiments, the primary cold head 222 is mounted inside the gas tank 23. It is understood that in other embodiments, the primary cold head 222 is mounted on the surface of the gas tank 23. In other words, during operation, the cryogenic refrigerator 22 can use the primary cold head 222 to cool the helium in the gas tank 23. This allows the high power of the primary cold head 222 on the cryogenic refrigerator 22 to pre-cool the helium, allowing the secondary cold head 221 to subsequently cool the phase separator 21 to liquefy the helium. This fully utilizes the characteristics of the cryogenic refrigerator 22 to transfer the cooling energy from the cryogenic refrigerator 22 to the coil body 11, enabling the coil body 11 to maintain a superconducting state in a sufficiently low temperature environment.

[0042] The primary cold head 222 is configured to provide a first cooling power within a first temperature range, and the secondary cold head 221 is configured to provide a second cooling power within a second temperature range, wherein the first cooling power is greater than the second cooling power, and the first temperature range is higher than the second temperature range. In some embodiments, the primary cold head 222 of the cryogenic refrigerator 22 can provide tens to hundreds of watts of cooling power within a temperature range of 30 Kelvin to 300 Kelvin. In some embodiments, the primary cold head 222 of the cryogenic refrigerator 22 of the present application is configured to maintain cooling within a temperature range of approximately 50 Kelvin, for example; while the secondary cold head 221 is configured, for example, to primarily maintain cooling within a temperature range of approximately 4 Kelvin, with a cooling power of, for example, only one to several watts. The temperature of the coil body 11 needs to be stabilized at 4.2 Kelvin to achieve a superconducting state. Therefore, to achieve a superconducting state, the coil body 11 needs to maintain heat exchange with the secondary cold head 221. It is understood that in other embodiments, the operating characteristics of the primary cold head 222 and the secondary cold head 221 can be configured to provide appropriate cooling power within a predetermined temperature range, based on the temperature requirements for achieving superconductivity and the need for rapid cooling of the superconducting coil 10. The primary cold head 222, with its high power, rapidly cools the helium in the gas tank 23. The cooled helium then enters the gas tank 23 and is liquefied by the low-power secondary cold head 221, thereby transferring cooling power to the coil body 11, enabling the coil body 11 to maintain a superconducting state in a sufficiently low temperature environment.

[0043] The specific structure of the cryogenic refrigerator 22 and the working principle of how to cool the primary cold head 222 and the secondary cold head 221 during operation can adopt the conventional method of the cryogenic refrigerator currently used in magnetic resonance imaging technology, which will not be elaborated here.

[0044] As shown in Figures 1 to 3, in some embodiments, the superconducting magnet 100 further includes a cold shield 30 disposed around the superconducting coil 10. The gas tank 23 is configured to exchange heat with the cold shield 30. For example, heat exchange can occur between the cold shield 30 and the gas tank 23 via a flexible connecting strip 31. In this manner, the gas tank 23 can be used to cool the cold shield 30, and the structural features of the cold shield 30 can be leveraged to reduce the radiated heat received by the superconducting coil 10, thereby preventing the ambient temperature of the coil body 11 from being affected by external thermal radiation.

[0045] It should be noted that the specific structure of the above-mentioned cold screen 30 and the flexible connecting belt 31, how the gas tank 23 exchanges heat with the cold screen 30 through the flexible connecting belt 31, and how the cold screen 30 reduces the working principle of radiant heat can all adopt the conventional method of cold screens currently used in magnetic resonance imaging technology, and will not be elaborated here.

[0046] As shown in Figures 1 to 3, in some embodiments, the superconducting magnet 100 further includes a room-temperature outer container 40, which has a vacuum chamber 41 formed inwardly therefrom; wherein the phase separator 21, the gas storage tank 23, and the superconducting coil 10 are all housed in the vacuum chamber 41, thereby creating a vacuum environment for the superconducting coil 10. This blocks convective heat transfer between the superconducting coil 10 and the interior of the room-temperature outer container 40, thereby preventing the ambient temperature of the superconducting coil 10 from being affected by convective heat transfer. It should be noted that the room-temperature outer container 40 is specifically formed as the outer shell of the superconducting magnet 100, and the vacuum chamber 41 formed inwardly therefrom specifically refers to the ability of the room-temperature outer container 40 to form a vacuum environment inwardly therefrom. The vacuum degree of the vacuum chamber 41 can be set according to specific requirements and will not be elaborated on here.

[0047] As shown in FIG2 , in some embodiments, the superconducting magnet 100 further includes an external refrigerator 50, which is connected and communicated with the gas tank 23; wherein the external refrigerator 50 is capable of cooling the helium. That is, when the superconducting magnet 100 of this embodiment is in operation, the external refrigerator 50 can be used to rapidly cool the helium in the gas tank 23 to cool the coil body 11. After the coil body 11 reaches a specified temperature, the heat exchange between the external refrigerator 50 and the gas tank 23 is disconnected, and the secondary cold head 221 cools the phase separator 21 to achieve liquefaction of the helium, ultimately maintaining the balance of the thermosiphon system of the liquid helium. This can greatly shorten the cooling time when the superconducting magnet 100 is in operation. It should be noted that the external refrigerator 50 can be set as a conventional refrigerator currently used in magnetic resonance imaging technology according to needs, which will not be elaborated here.

[0048] In some embodiments, a gas valve 1011 is installed on the passage 101 connecting the external refrigerator 50 and the gas storage tank 23. Gas valve 1011 can control the opening and closing of passage 101. In other words, the opening and closing of the connection between the external refrigerator 50 and the gas storage tank 23 can be achieved through gas valve 1011. In this way, the intervention of the external refrigerator 50 in cooling the helium gas can be controlled to meet the subsequent use requirements of the low-temperature refrigerator 22 to liquefy the helium into liquid helium. It should be noted that the gas valve 1011 can be configured as a manual valve, a solenoid valve, etc. as required, and will not be elaborated here.

[0049] As shown in FIG3 , in some embodiments, an inlet pipe 231 and an outlet pipe 232 are connected and communicated with the gas storage tank 23. Refrigerant can be introduced through the inlet pipe 231 to cool the gas storage tank 23 and the coil body 11. After reaching thermal equilibrium, helium can be introduced into the inlet pipe 231. Taking advantage of the different specific gravities between helium and the refrigerant, the refrigerant can be discharged out of the outlet pipe 232 until it is empty, and then the inlet pipe 231 and the outlet pipe 232 can be closed. For example, the refrigerant can include liquid nitrogen, liquid carbon dioxide, liquid propane, etc. For example, liquid nitrogen can be introduced into the gas storage tank 23 through the inlet pipe 231. After reaching thermal equilibrium, the introduced liquid nitrogen can be discharged out of the outlet pipe 232 under the pressure of the helium introduced into the inlet pipe 231, thereby emptying the liquid nitrogen from the gas storage tank 23. That is, in the process of cooling the coil body 11, the superconducting magnet 100 of this embodiment can first introduce liquid nitrogen through the inlet pipe 231, and use the liquid nitrogen to cool the gas storage tank 23 and the coil body 11. After reaching thermal equilibrium, helium is introduced into the inlet pipe 231. Taking advantage of the different specific gravities between helium and liquid nitrogen, the liquid nitrogen can be discharged outward from the outlet pipe 232 until it is empty. The inlet pipe 231 and the outlet pipe 232 are then closed. The low-temperature refrigerator 22 is then turned on, and the first-stage cold head 222 is used to cool the gas storage tank 23. The second-stage cold head 221 is used to cool the phase separator 21 to achieve liquefaction of the helium, and finally maintain the balance of the liquid helium thermosiphon system. Since liquid nitrogen is cheaper and easier to obtain than helium, the above method can not only greatly shorten the cooling time of the superconducting coil 10, but also reduce costs. It should be noted that the liquid nitrogen mentioned above reaches thermal equilibrium in the gas storage tank 23 , specifically, the temperature of the gas storage tank 23 into which the liquid nitrogen is introduced is consistent with the temperature of the liquid nitrogen, and no heat exchange occurs between the two.

[0050] It should be noted that the temperature of liquid nitrogen is generally 77 Kelvin, and after the cryogenic refrigerator 22 is turned on, the first-stage cold head 222 can reduce the temperature of the helium in the gas tank 23 to 50 Kelvin, and the second-stage cold head 221 can reduce the temperature of the liquid helium in the phase separator 21 to 4 Kelvin. Therefore, during the process of introducing liquid nitrogen into the gas tank 23 through the air inlet pipe 231 until the liquid nitrogen reaches thermal equilibrium, the cryogenic refrigerator 22 does not need to be turned on.

[0051] Referring to FIG. 4 , in some embodiments, the superconducting magnet 100 further includes a pipe 24 located outside the cold shield 30, with both ends of the pipe 24 connected to a gas storage tank 23. Helium in the gas storage tank 23 enters the pipe 24, thereby enabling heat exchange with the cold shield 30. The pipe 24 is further provided with at least one additional gas storage tank 25 connected to the pipe 24 for storing helium. As shown in FIG. 4 , the pipe 24 is provided with multiple additional gas storage tanks 25 connected in series. The additional gas storage tanks 25 are connected to the pipe 24, thereby increasing the gas storage capacity. Furthermore, the additional gas storage tanks 25 can contact the cold shield 30, thereby further enabling heat exchange with the cold shield 30.

[0052] In some embodiments, referring to FIG5 , the superconducting magnet 100 further includes a detection mechanism 60 that can monitor the discharge of liquid nitrogen from the gas tank 23 to determine whether the liquid nitrogen in the gas tank 23 has been completely discharged. This allows the superconducting magnet 100 to control the cryogenic refrigerator 22 to start after the liquid nitrogen in the gas tank 23 has been completely discharged.

[0053] For example, the detection mechanism 60 can determine whether the liquid nitrogen in the gas storage tank 23 has been exhausted by detecting whether helium is mixed in the liquid nitrogen discharged from the gas outlet pipe 232; or, by comparing the weight of the superconducting magnet 100 before and after the liquid nitrogen is introduced, the detection mechanism 60 can determine whether the liquid nitrogen in the gas storage tank 23 has been exhausted by weighing the superconducting magnet 100.

[0054] In some embodiments, the passage 101 connecting the external refrigerator 50 and the gas storage tank 23 may share a pipe with the air inlet pipe 231 and the air outlet pipe 232. In other embodiments, the passage 101 connecting the external refrigerator 50 and the gas storage tank 23 may be independent of the air inlet pipe 231 and the air outlet pipe 232.

[0055] In addition, the present application also provides a magnetic resonance imaging device, comprising the superconducting magnet 100 described in the above embodiments.

[0056] In summary, the superconducting magnet 100 for which protection is sought in the present application utilizes heat exchange between the heat exchange tube 12 and the coil body 11 to reduce the ambient temperature of the coil body 11 so that the superconducting coil 10 reaches a superconducting state. In this way, the amount of liquid helium used in the superconducting magnet 100 can be reduced, thereby saving liquid helium resources and reducing the overall production cost of the superconducting magnet 100.

[0057] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] Those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present invention and are not intended to limit the present invention. Any appropriate changes and modifications to the above embodiments are intended to fall within the scope of protection claimed by the present invention as long as they are within the spirit of the present invention.

Claims

1. A superconducting magnet, comprising: A superconducting coil (10) comprises a coil body (11) and a heat exchange tube (12), wherein the heat exchange tube (12) is mounted on the coil body (11) and is configured to perform heat exchange with the coil body (11); The refrigeration mechanism (20) comprises a low-temperature refrigerator (22) and a gas storage tank (23), wherein the gas storage tank (23) is connected to the heat exchange pipe (12).

2. The superconducting magnet according to claim 1, wherein: The refrigeration mechanism (20) comprises a phase separator (21), the phase separator (21) being connected and communicated with the gas storage tank (23) and the heat exchange tube (12) respectively, so that the gas storage tank (23) is communicated with the heat exchange tube (12) through the phase separator (21), the low-temperature refrigerator (22) has a secondary cold head (221), and the phase separator (21) is installed on the secondary cold head (221) and is configured to perform heat exchange with the secondary cold head (221).

3. The superconducting magnet according to claim 2, wherein: The superconducting magnet (100) further comprises a room temperature outer container (40), wherein a vacuum chamber (41) is formed inwardly of the room temperature outer container (40), and the phase separator (21) and the superconducting coil (10) are both accommodated in the vacuum chamber (41).

4. The superconducting magnet according to any one of claims 1 to 3, wherein: The low-temperature refrigerator (22) further comprises a primary cold head (222), and the gas storage tank (23) is mounted on the primary cold head (222) and is configured to perform heat exchange with the primary cold head (222).

5. The superconducting magnet according to claim 4, wherein: The primary cold head (222) is configured to cool the helium in the gas storage tank (23), and the secondary cold head (221) is configured to liquefy the helium entering the phase separator (21) after being cooled by the primary cold head (222).

6. The superconducting magnet according to claim 5, wherein: The first-stage cold head (222) is configured to provide a first cooling power in a first temperature range, and the second-stage cold head (221) is configured to provide a second cooling power in a second temperature range, wherein the first cooling power is greater than the second cooling power, and the first temperature range is higher than the second temperature range.

7. The superconducting magnet according to claim 6, wherein: The first temperature ranges from 30 Kelvin to 300 Kelvin.

8. The superconducting magnet according to any one of claims 1 to 7, wherein: The superconducting magnet (100) further comprises an external refrigerator (50), wherein the external refrigerator (50) is connected to and communicates with the gas storage tank (23) and is configured to perform heat exchange with the gas storage tank (23).

9. The superconducting magnet according to claim 8, wherein: A gas valve (1011) is installed on the passage (101) connecting the external refrigerator (50) and the gas storage tank (23), and the gas valve is configured to control the on / off of the passage (101).

10. The superconducting magnet according to any one of claims 1 to 9, wherein: The superconducting magnet (100) further comprises a cold shield (30), wherein the cold shield (30) is arranged at the periphery of the superconducting coil (10), and the gas storage tank (23) is configured to perform heat exchange with the cold shield (30).

11. The superconducting magnet according to claim 10, wherein: The cold shield (30) and the gas storage tank (23) perform heat exchange via a flexible connecting belt (31).

12. The superconducting magnet according to claim 10 or 11, further comprising a pipe (24) located outside the cold shield (30), and both ends of the pipe (24) are respectively connected to the gas storage tank (23).

13. The superconducting magnet according to claim 12, wherein the pipeline (24) is provided with at least one additional gas storage tank (25) connected to the pipeline (24), and the additional gas storage tank (25) is configured to perform heat exchange on the cold shield.

14. The superconducting magnet according to any one of claims 1 to 13, wherein: The gas storage tank (23) is connected to and communicates with an air inlet pipe (231) for introducing refrigerant into the gas storage tank (23) and an air outlet pipe (232) for conducting the refrigerant out.

15. The superconducting magnet according to claim 14, wherein: The cryogen includes liquid nitrogen.

16. The superconducting magnet according to claim 15, wherein: The superconducting magnet (100) further comprises a detection mechanism, which is configured to monitor the liquid nitrogen discharged from the outlet pipe (232).

17. The superconducting magnet according to claim 15 or 16, wherein: The gas storage tank (23) is configured to discharge the liquid nitrogen stored therein from the gas outlet pipe (232) when helium gas is input from the gas inlet pipe (231).

18. The superconducting magnet according to claim 1 or 2, wherein: The superconducting magnet (100) further comprises a room temperature outer container (40), wherein a vacuum chamber (41) is formed inwardly of the room temperature outer container (40); The gas storage tank (23) is accommodated in the vacuum chamber (41).

19. The superconducting magnet according to any one of claims 1 to 18, wherein: The primary cold head (222) is installed inside the gas storage tank (23), and / or the secondary cold head (221) is installed inside the phase separator (21).

20. A magnetic resonance imaging device, comprising the superconducting magnet (100) according to any one of claims 1 to 19.

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