High-magnetic-field high-uniformity superconducting magnet system for nuclear magnetic resonance

Abstract

The invention discloses a high-magnetic-field and high-uniformity superconducting magnet system for nuclear magnetic resonance, belongs to the technical field of nuclear magnetic resonance, and solves the problem of how to design a high-magnetic-field-intensity and high-uniformity superconducting magnet system. A high-field area in the magnet is a coil using a niobium-tin superconducting wire, and a low-field area in the magnet uses a coil using a niobium-titanium superconducting wire; the main coils are connected in series to work together, and can generate an effective central magnetic field intensity of 18.8 T when operating at a liquid helium temperature; the design uniformity of a central magnetic field can be superior to 0.01 ppm in a spherical range with the diameter of 1cm; the main magnetic field coil can shield more than 90% of external electromagnetic interference; the shielding coil can effectively control the size of a stray field of a magnet system, and a 5Gs line stray field can be limited in a 1.5 m ellipsoid and a 2.5 m ellipsoid in the radial direction and the axial direction respectively. The method is suitable for a nuclear magnetic resonance spectrometer, animal imaging, Fourier transform ion cyclotron resonance and other scenes.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear magnetic resonance, and relates to a high-magnetic-field and high-uniformity superconducting magnet system for nuclear magnetic resonance. Background Art

[0002] Nuclear magnetic resonance (NMR) spectroscopy is one of the most commonly used and direct means to identify the structure of pure (liquid or solid) compounds and mixtures in the fields of chemistry, physics, biology, medicine, materials, etc. It is one of the few technologies that can be used to detect three states of matter. The structural analysis of almost all organic or biological molecules and many inorganic molecules begins with nuclear magnetic resonance spectroscopy technology.

[0003] Nuclear magnetic resonance spectrometers come in various forms, but their basic components are the same, including: a magnet that provides a high-uniformity and high-stability main magnetic field, components that generate pulses and receive the generated NMR signals, a probe for placing samples, hardware that stabilizes the main magnetic field and optimizes the signal, and a computer that controls the operation of the instrument and processes the NMR signals.

[0004] The magnet that provides the main magnetic field is the most critical core component of the nuclear magnetic resonance system. The earliest NMR spectrometers used electromagnets and worked in continuous wave mode, which had the characteristics of low sensitivity and poor stability. Modern desktop permanent magnet instruments are low-cost and easy to use and maintain, but the sensitivity is still very low. At present, most scientific research spectrometers use superconducting magnets and operate in pulse Fourier transform mode. Compared with ordinary copper conductor materials, superconducting wires have higher current density, and their current carrying capacity is two to three orders of magnitude of traditional conventional conductive metal materials. The superconducting magnets developed based on superconducting wires have higher magnetic field strength, more compact magnet structure, and better magnetic field stability. At the same time, since the chemical shift and its difference increase with the increase of field strength, the strong magnetic field of the superconducting magnet is more effective in distinguishing nuclear magnetic signals.

[0005] High uniformity and high magnetic field coils can be achieved by combining superconducting wires of different specifications. Existing domestic patent technologies (CN101552077B, CN112908609B) can generate high uniformity magnetic fields, but they use NMR superconducting coils made of niobium titanium (NbTi) conductors, so the magnetic field is only 9.4T (corresponding to a 400MHz proton resonance frequency). To generate a magnetic field above 9.4T, a combination of niobium titanium and niobium tin (Nb3Sn, Nb3(Ta)Sn, etc.) coils is required. The patent document "A High Magnetic Field Superconducting Magnet System" (CN113889313B) gives a preliminary coil combination structure, but the magnetic field strength is 14T, and it is used in the field of nuclear magnetic resonance imaging (MRI), not nuclear magnetic resonance spectroscopy (NMR). At the same time, the patent document does not consider the influence of electromagnetic force on brittle niobium tin materials. Summary of the invention

[0006] The technical solution of the present invention is used to solve the problem of how to design a superconducting magnet system with high magnetic field intensity and high uniformity.

[0007] The present invention solves the above technical problems through the following technical solutions: A high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance comprises: a main coil subsystem, a compensation coil subsystem, a shielding coil subsystem and an anti-interference coil subsystem; the main coil subsystem comprises: a first niobium-tin coil, a second niobium-tin coil, a third niobium-tin coil, a first niobium-titanium coil and a second niobium-titanium coil; the first niobium-tin coil, the second niobium-tin coil, the third niobium-tin coil, the first niobium-titanium coil and the second niobium-titanium coil are hierarchically and coaxially nested from the inside to the outside along the radial direction; at least one of the first niobium-tin coil, the second niobium-tin coil and the third niobium-tin coil is provided with a binding layer on the outside; at least one of the first niobium-titanium coil and the second niobium-titanium coil is provided with a binding layer on the outside; the compensation coil subsystem comprises: a first low-order magnetic field harmonic component compensation coil, a second low-order magnetic field harmonic component compensation coil, a first high-order magnetic field harmonic component elimination coil, a second high-order magnetic field harmonic component elimination coil, a first high-order magnetic field harmonic component compensation coil and a second high-order magnetic field harmonic component compensation coil; the first low-order magnetic field harmonic component The component compensation coil, the first high-order magnetic field harmonic component elimination coil, the first high-order magnetic field harmonic component compensation coil, the second high-order magnetic field harmonic component compensation coil, the second high-order magnetic field harmonic component elimination coil, and the second low-order magnetic field harmonic component compensation coil are symmetrically coaxially sleeved on the outside of the main coil subsystem from top to bottom; the shielding coil subsystem is arranged on the outermost side of the magnet; the anti-interference coil is arranged inside the main coil subsystem; the main coil subsystem, the compensation coil subsystem, and the shielding coil subsystem work together in series, with the same working current and are excited by the same power supply; the function of the compensation coil subsystem is to compensate for the second-order, fourth-order, and sixth-order inhomogeneous magnetic fields of the long solenoid structure magnetic field of the main coil subsystem; the working current direction of the shielding coil subsystem is opposite to the working current direction of the main coil subsystem and the compensation coil subsystem; the anti-interference coil subsystem has no working current in the initial state, and the anti-interference coil subsystem is electromagnetically coupled with the main coil subsystem, the compensation coil subsystem, and the shielding coil subsystem.

[0008] Furthermore, for the multiple coils in the main coil subsystem, the axial length of the coil radially close to the center is less than or equal to the axial length of the outer coil radially adjacent thereto, that is, the axial length of the first niobium-tin coil is less than or equal to the axial length of the second niobium-tin coil, the axial length of the second niobium-tin coil is less than or equal to the axial length of the third niobium-tin coil, the axial length of the third niobium-tin coil is less than or equal to the axial length of the first niobium-titanium coil, and the axial length of the first niobium-titanium coil is less than or equal to the axial length of the second niobium-titanium coil.

[0009] Furthermore, the current carrying capacity of the superconducting wires respectively used by the multiple coils in the main coil subsystem is, under the same environment, that the current carrying capacity of the wire radially close to the center is greater than or equal to that of the superconducting wire used by the radially adjacent outer coil.

[0010] Furthermore, the main coil subsystem, the compensation coil subsystem, the shielding coil subsystem and the anti-interference coil subsystem are all impregnated with paraffin or epoxy.

[0011] Furthermore, the shielding coil subsystem includes: a first shielding coil and a second shielding coil; the first shielding coil and the second shielding coil are two identical circular rings, the first shielding coil and the second shielding coil are symmetrical from top to bottom, and are coaxially sleeved on the outside of the compensation coil subsystem.

[0012] Furthermore, the anti-interference coil includes: an anti-interference main coil, a first anti-interference end compensation coil and a second anti-interference end compensation coil; the anti-interference main coil is a cylindrical coil, the first anti-interference end compensation coil and the second anti-interference end compensation coil are both circular rings, and the first anti-interference end compensation coil and the second anti-interference end compensation coil are symmetrically arranged inside or outside the anti-interference main coil.

[0013] Furthermore, the shielding coil subsystem adopts a reverse field solenoid shielding coil.

[0014] Furthermore, the steps for making the binding layer provided outside the niobium tin coil are: winding the niobium tin coil on the frame, heat treating the niobium tin coil, epoxy vacuum impregnating the niobium tin coil, processing the outer surface of the impregnated niobium tin coil to form a space required for winding the binding layer, and winding the binding layer.

[0015] Furthermore, the steps for making the binding layer provided outside the niobium-titanium coil are: the niobium-titanium coil is wound on the frame, the niobium-titanium coil is vacuum impregnated with epoxy, a space required for winding the binding layer is processed on the outer surface of the impregnated niobium-titanium coil, and the binding layer is wound.

[0016] Furthermore, the axial winding length of the binding layer is less than or equal to the axial length of the coil, but not less than 50% of the coil length; the material of the binding layer is pure metal wire or metal wire with an insulating layer.

[0017] The advantages of the present invention are: The high magnetic field strength and high uniformity superconducting magnet system for nuclear magnetic resonance of the present invention is an 800MHz superconducting nuclear magnetic resonance spectrometer magnet; the internal high field region of the magnet of the present invention is a coil using a niobium-tin superconducting wire, and the external low field region is a coil using a niobium-titanium superconducting wire, and all the coils are nested and assembled with a common central axis inside and outside; the main coil, the compensation coil, and the shielding coil work together in series and operate at liquid helium temperature to generate an effective central magnetic field strength of 18.8T (corresponding to a proton resonance frequency of 800MHz); through the optimized design of the main coil and each compensation coil, the uniformity of the central magnetic field design is within a spherical range of 1cm in diameter. The range can be better than 0.01ppm; the anti-interference coil can shield more than 90% of the external electromagnetic interference without damaging the long-term stability of the main magnet's magnetic field; the introduction of the shielding coil can effectively control the stray field size of the magnet system, and the 5Gs line (5 Gaussian line) stray field can be limited to 1.5m and 2.5m ellipsoids in the radial and axial directions respectively; the invention is suitable for high magnetic field strength and high uniformity magnets with a diameter of 50-200mm, and is used in scenes such as nuclear magnetic resonance spectrometer (NMR), animal imaging (pre-clinicMRI), Fourier transform ion cyclotron resonance (FT-ICR), etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural marking diagram of each subsystem of an axial one-half cross-sectional view of a high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to the first embodiment of the present invention; Figure 2 It is a structural marking diagram of each coil in an axial one-half cross-sectional view of a high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to the first embodiment of the present invention; Figure 3 1 is a structural diagram of an anti-interference coil subsystem of a high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to the first embodiment of the present invention; Figure 4 This is a schematic diagram of a binding layer provided outside the niobium-tin or niobium-titanium coil of a high-field and high-uniformity superconducting magnet system for nuclear magnetic resonance according to the first embodiment of the present invention; Figure 5 This is a magnetic field uniformity distribution diagram on spherical surfaces of different sizes of a high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance in the first embodiment of the present invention; Figure 6 This is a superconducting magnet stray field distribution diagram of a high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to the first embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0020] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments: Embodiment 1 like Figure 1 As shown, a high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance includes: a main coil subsystem 10, a compensation coil subsystem 20, a shielding coil subsystem 30 and an anti-interference coil subsystem 40.

[0021] like Figure 2 As shown, the main coil subsystem 10 includes: a first niobium-tin coil 101 , a second niobium-tin coil 102 , a third niobium-tin coil 103 , a first niobium-titanium coil 104 , and a second niobium-titanium coil 105 .

[0022] The first niobium tin coil 101, the second niobium tin coil 102, the third niobium tin coil 103, the first niobium titanium coil 104, and the second niobium titanium coil 105 are all cylindrical coils. The first niobium tin coil 101, the second niobium tin coil 102, the third niobium tin coil 103, the first niobium titanium coil 104, and the second niobium titanium coil 105 are concentrically and coaxially nested in layers from the inside to the outside along the radial direction, that is, the first niobium tin coil 101 is concentrically and coaxially nested inside the second niobium tin coil 102, the second niobium tin coil 102 is concentrically and coaxially nested inside the third niobium tin coil 103, the third niobium tin coil 103 is concentrically and coaxially nested inside the first niobium titanium coil 104, and the first niobium titanium coil 104 is concentrically and coaxially nested inside the second niobium titanium coil 105.

[0023] For the multiple coils in the main coil subsystem 10, the axial length of the coil radially close to the center is less than or equal to the radially adjacent outer coil, that is, the axial length of the first niobium tin coil 101 is less than or equal to the axial length of the second niobium tin coil 102, the axial length of the second niobium tin coil 102 is less than or equal to the axial length of the third niobium tin coil 103, the axial length of the third niobium tin coil 103 is less than or equal to the axial length of the first niobium titanium coil 104, and the axial length of the first niobium titanium coil 104 is less than or equal to the axial length of the second niobium titanium coil 105.

[0024] The current carrying capacity of the superconducting wires respectively used in the multiple coils in the main coil subsystem 10 is that, under the same environment, the current carrying capacity of the wire radially close to the center is greater than or equal to the superconducting wire used in the radially adjacent outer coil, that is, the current carrying capacity of the first niobium tin coil 101 is greater than or equal to the current carrying capacity of the second niobium tin coil 102, the current carrying capacity of the second niobium tin coil 102 is greater than or equal to the current carrying capacity of the third niobium tin coil 103, the current carrying capacity of the third niobium tin coil 103 is greater than or equal to the current carrying capacity of the first niobium titanium coil 104, and the current carrying capacity of the first niobium titanium coil 104 is greater than or equal to the current carrying capacity of the second niobium titanium coil 105.

[0025] The main coil subsystem 10, the compensation coil subsystem 20, the shielding coil subsystem 30 and the anti-interference coil subsystem 40 are all impregnated with paraffin or epoxy to ensure structural rigidity.

[0026] The diameter of the first NbSn coil 101 is about 80 mm to produce a room temperature aperture of 54 mm.

[0027] At least one of the first niobium-tin coil 101 , the second niobium-tin coil 102 , and the third niobium-tin coil 103 is provided with a binding layer on its exterior, and the binding layer is used to prevent electromagnetic force from damaging the niobium-tin material coil.

[0028] Niobium-titanium superconducting wire is generally used to make magnets below 10T because of its low critical magnetic field. For magnets above 10T, superconducting conductors with high critical magnetic fields such as niobium-tin are needed. Niobium-tin superconducting conductor is a composite of niobium-tin raw materials, bronze, copper-based materials and other materials. Niobium-tin conductors need to undergo high-temperature heat treatment to form conductors with superconducting properties, and have the disadvantages of poor mechanical properties and high brittleness. Therefore, for superconducting coils using niobium-tin materials, it is very important to have measures to maintain the strength of the coils to avoid electromagnetic force from damaging the niobium-tin materials. When the superconducting coils wound by superconducting materials are in working state, the interaction between current and magnetic field will form an outward-expanding electromagnetic force on the superconducting coils. This electromagnetic force must be well controlled so that the electromagnetic strain of the coil under electromagnetic force meets the design requirements. The current-carrying performance of niobium-tin materials is related to their strain state. Controlling the strain of the coil can control the decay of the current-carrying capacity of the superconducting material caused by electromagnetic force. Niobium-tin superconducting coils generally use vacuum impregnation (paraffin or epoxy) and external winding binding layers of the coil to control their strain state. Vacuum impregnation is used to fill the gaps between layers and turns of the superconducting coil, which can maintain the rigidity of the superconducting coil and resist the electromagnetic pressure in the axial direction of the coil. The binding layer is a way to control the influence of radial force on the coil. Usually, non-magnetic high-strength materials such as 304, 316, 316L, 316LN stainless steel are used on the outside of the superconducting coil wound by superconducting conductors. Binding layers of different radial thicknesses are wound according to the size of the electromagnetic force. The structure of the binding layer is as follows: Figure 4As shown (for a clear structure, other parts such as the coil skeleton have been hidden). The axial winding length of the binding layer is less than or equal to the axial length of the superconducting coil, but not less than 50% of the coil length. Therefore, gaps are left at the upper and lower ends of the binding layer. The binding layer material can be pure metal wire or metal wire with insulation (such as glass cloth sleeve, etc.); it can be directly dry-wound on the outside of the coil, or it can be vacuum impregnated together with the coil after the winding is completed; the binding layer material can be wound before the niobium-tin superconducting wire is heat-treated, or it can be wound after the niobium-tin superconducting wire is heat-treated.

[0029] The main steps for making the binding layer provided on the outside of the niobium tin coil are: winding the niobium tin coil on the skeleton, heat treating the niobium tin coil, epoxy vacuum impregnating the niobium tin coil, processing the space required for winding the binding layer on the outer surface of the impregnated niobium tin coil, and winding the binding layer. When post-processing the binding layer space, it is recommended that the overall axial length is less than the length of the coil, which is mainly to ensure that other parts at the end are not damaged during processing. The binding layer material in this manufacturing method is wound after heat treatment, so the mechanical strength of the binding layer material will not be degraded due to high-temperature heat treatment. The method of the embodiment of the present invention can use less binding material to achieve the control of electromagnetic force, so that the overall structure of the magnet is more compact.

[0030] A binding layer is also provided on the outside of the niobium-titanium coil. The main steps for making the binding layer provided on the outside of the niobium-titanium coil are: the niobium-titanium coil is wound on the frame, the niobium-titanium coil is vacuum impregnated with epoxy, the space required for winding the binding layer is processed on the outer surface of the impregnated niobium-titanium coil, and the binding layer is wound; the axial winding length of the binding layer is less than or equal to the axial length of the niobium-titanium coil, but not less than 50% of the length of the niobium-titanium coil.

[0031] like Figure 2As shown, the compensation coil subsystem 20 includes: a first low-order magnetic field harmonic component compensation coil 201, a second low-order magnetic field harmonic component compensation coil 202, a first high-order magnetic field harmonic component elimination coil 203, a second high-order magnetic field harmonic component elimination coil 204, a first high-order magnetic field harmonic component compensation coil 205, and a second high-order magnetic field harmonic component compensation coil 206; the first low-order magnetic field harmonic component compensation coil 201 and the second low-order magnetic field harmonic component compensation coil 202 are two identical circular rings, and the first high-order magnetic field harmonic component elimination coil 203 and the second high-order The magnetic field harmonic component elimination coil 204 is two identical circular rings, and the first high-order magnetic field harmonic component compensation coil 205 and the second high-order magnetic field harmonic component compensation coil 206 are two identical circular rings; the first low-order magnetic field harmonic component compensation coil 201, the first high-order magnetic field harmonic component elimination coil 203, the first high-order magnetic field harmonic component compensation coil 205, the second high-order magnetic field harmonic component compensation coil 206, the second high-order magnetic field harmonic component elimination coil 204, and the second low-order magnetic field harmonic component compensation coil 202 are symmetrically coaxially sleeved on the outside of the main coil subsystem 10 from top to bottom.

[0032] like Figure 2 As shown, the shielding coil subsystem 30 is arranged at the outermost side of the magnet, and the shielding coil subsystem 30 includes: a first shielding coil 301 and a second shielding coil 302; the first shielding coil 301 and the second shielding coil 302 are two identical circular rings, the first shielding coil 301 and the second shielding coil 302 are symmetrical from top to bottom, and are coaxially sleeved on the outside of the compensation coil subsystem 20; the number of shielding coils can be greater than 2.

[0033] like Figure 3 As shown, the anti-interference coil subsystem 40 includes: an anti-interference main coil 401, a first anti-interference end compensation coil 402 and a second anti-interference end compensation coil 403; the anti-interference main coil 401 is a cylindrical coil, the first anti-interference end compensation coil 402 and the second anti-interference end compensation coil 403 are both circular rings, and the first anti-interference end compensation coil 402 and the second anti-interference end compensation coil 403 are symmetrically arranged inside or outside the anti-interference main coil 401; the anti-interference coil subsystem 40 is arranged inside the main coil subsystem 10, and the anti-interference coil subsystem 40 of this embodiment is sleeved on the outside of the second niobium tin coil 102, and the anti-interference coil subsystem 40 can also be sleeved on the outside of the first niobium tin coil 101, the third niobium tin coil 103 or the first niobium titanium coil 104.

[0034] Working principle of magnets: The main coil subsystem 10, the compensation coil subsystem 20, and the shielding coil subsystem 30 are connected in series and work together, have the same working current, and are excited by the same power supply.

[0035] The function of the compensation coil subsystem 20 is to compensate for the second-order, fourth-order, sixth-order and other inhomogeneous magnetic fields of the long solenoid structure magnetic field of the main coil subsystem 10; using multiple sets of compensation coils can make the harmonic components of the axial magnetic field of the magnet system less than 0.01ppm.

[0036] The working current direction of the shielding coil subsystem 30 is opposite to the working current direction of the main coil subsystem 10 and the compensation coil subsystem 20, so as to reduce the stray field size of the magnet and reduce the installation area requirement of the user.

[0037] The shielding coil subsystem 30 adopts a reverse field solenoid shielding coil; The anti-interference coil subsystem 40 has no working current in the initial state; the electromagnetic coupling between the anti-interference coil subsystem 40 and the main coil subsystem 10, the compensation coil subsystem 20, and the shielding coil subsystem 30 is used to offset the magnetic field changes generated by the main magnet main coil subsystem 10, the compensation coil subsystem 20, and the shielding coil subsystem 30 at the center of the magnet to the external electromagnetic disturbance; this is because when there is an external electromagnetic disturbance, the main magnet has a magnetic field response to the disturbance. This response will affect (usually deteriorate) the magnetic field quality at the center of the magnetic field; the anti-interference coil subsystem 40 can generate a response opposite to the main magnet through electromagnetic induction with the main magnet, thereby eliminating the electromagnetic interference of the magnet to the outside. At the same time, due to the existence of the anti-interference coil subsystem 40, the magnetic field attenuation rate of the entire magnet will not be aggravated. On the contrary, through electromagnetic coupling with the main magnet, the anti-interference coil subsystem 40 can reduce the magnetic field attenuation rate of the entire magnet and increase the magnetic field stability of the magnet; the first anti-interference end compensation coil 402 and the second anti-interference end compensation coil 403 of the anti-interference coil subsystem 40 make the anti-interference coil subsystem 40 respond to the magnetic field of the main magnet without damaging the magnetic field uniformity of the main magnet.

[0038] Figure 5 It is a magnetic field uniformity distribution diagram on spherical surfaces of different sizes of the high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance of the present invention; Figure 5 As shown, the magnetic field uniformity distribution equipotential lines within the 2 cm sphere at the center of the coil have a peak-to-peak uniformity of better than 0.025 ppm within the 2 cm sphere and a peak-to-peak uniformity of better than 0.01 ppm within the 1 cm sphere.

[0039] Figure 6 is a superconducting magnet stray field distribution diagram of the high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance of the present invention; Figure 6 As shown, the 5Gs line (5 Gaussian line) stray field can be confined within the 1.5m and 2.5m ellipsoids in the radial and axial directions respectively.

[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance, characterized in that: The main coil subsystem includes: the first, second and third niobium tin coils and the first and second niobium titanium coils. The first, second and third niobium tin coils and the first and second niobium titanium coils are nested concentrically and coaxially in layers from the inside to the outside along the radial direction; at least one of the first, second and third niobium tin coils is provided with a binding layer on the outside, and at least one of the first and second niobium titanium coils is provided with a binding layer on the outside; the compensation coil subsystem includes: the first and second low-order magnetic field harmonic component compensation coils, the first and second high-order magnetic field harmonic component elimination coils and the first and second high-order magnetic field harmonic component compensation coils; the first low-order magnetic field harmonic component compensation coil, the first high-order magnetic field harmonic component elimination coil, the first high-order magnetic field harmonic component compensation coil, The second higher-order magnetic field harmonic component compensation coil, the second higher-order magnetic field harmonic component elimination coil, and the second lower-order magnetic field harmonic component compensation coil are symmetrically coaxially sleeved on the outside of the main coil subsystem from top to bottom; the shielding coil subsystem is arranged on the outermost side of the magnet; the anti-interference coil subsystem is arranged inside the main coil subsystem; the main coil subsystem, the compensation coil subsystem, and the shielding coil subsystem are connected in series, and the working currents are consistent; the working current direction of the shielding coil subsystem is opposite to the working current direction of the main coil subsystem and the compensation coil subsystem; the anti-interference coil subsystem has no working current in the initial state, and it is electromagnetically coupled with the main coil subsystem, the compensation coil subsystem, and the shielding coil subsystem.

2. The high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to claim 1, characterized in that: For the multiple coils in the main coil subsystem, the axial length of the coil radially close to the center is less than or equal to the radially adjacent outer coil, that is, the axial length of the first niobium tin coil is less than or equal to the axial length of the second niobium tin coil, the axial length of the second niobium tin coil is less than or equal to the axial length of the third niobium tin coil, the axial length of the third niobium tin coil is less than or equal to the axial length of the first niobium titanium coil, and the axial length of the first niobium titanium coil is less than or equal to the axial length of the second niobium titanium coil.

3. The high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to claim 1, characterized in that: The current carrying capacity of the superconducting wires used by the multiple coils in the main coil subsystem is such that, under the same environment, the current carrying capacity of the wire radially close to the center is greater than or equal to the superconducting wire used by the radially adjacent outer coil.

4. The high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to claim 1, characterized in that: The main coil subsystem, compensation coil subsystem, shielding coil subsystem and anti-interference coil subsystem are all impregnated with paraffin or epoxy.

5. The high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to claim 1, characterized in that: The shielding coil subsystem includes: a first shielding coil and a second shielding coil; the first shielding coil and the second shielding coil are two identical circular rings, the first shielding coil and the second shielding coil are symmetrical from top to bottom, and are coaxially sleeved outside the compensation coil subsystem.

6. The high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to claim 1, characterized in that: The anti-interference coil subsystem includes: an anti-interference main coil, a first anti-interference end compensation coil and a second anti-interference end compensation coil; the anti-interference main coil is a cylindrical coil, the first anti-interference end compensation coil and the second anti-interference end compensation coil are both circular rings, and the first anti-interference end compensation coil and the second anti-interference end compensation coil are symmetrically arranged inside or outside the anti-interference main coil.

7. The high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to claim 1, characterized in that: The shielding coil subsystem adopts reverse field solenoid shielding coil.

8. The high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to claim 1, characterized in that: The steps of making the binding layer set outside the niobium tin coil are: winding the niobium tin coil on the frame, heat treating the niobium tin coil, epoxy vacuum impregnating the niobium tin coil, processing the space required for winding the binding layer on the outer surface of the impregnated niobium tin coil, and winding the binding layer.

9. The high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to claim 1, characterized in that: The steps for making the binding layer outside the niobium titanium coil are: winding the niobium titanium coil on the frame, vacuum impregnating the niobium titanium coil with epoxy, processing the outer surface of the impregnated niobium titanium coil to form a space required for winding the binding layer, and winding the binding layer.

10. The high magnetic field and high uniformity superconducting magnet system for nuclear magnetic resonance according to claim 8 or 9, characterized in that: The axial winding length of the binding layer is less than or equal to the axial length of the coil, but not less than 50% of the coil length; the material of the binding layer is pure metal wire or metal wire with an insulating layer.

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