Spliced high-temperature superconducting magnetic shielding device and combined device

Abstract

The invention relates to a spliced high-temperature superconducting magnetic shielding device and a combined device, which are used for at least solving the problem that a magnetic shielding device made of a soft magnetic material generates magnetic noise, and residual magnetism or magnetic noise can be reduced by at least 1-3 orders of magnitude after the spliced high-temperature superconducting magnetic shielding device and the combined device are combined with the spliced high-temperature superconducting magnetic shielding device. Comprising a spliced magnetic shielding barrel formed by splicing and enclosing a plurality of blocks, the blocks are superconductive blocks formed by sintering high-temperature superconductive powder, the splicing seams between the adjacent blocks are filled with the superconductive powder, the splicing seams between the adjacent blocks are adhered and sealed by superconductive tapes, and high-temperature superconduction means that the temperature of liquid nitrogen generating a superconductive phenomenon is greater than or equal to 77K.

Description

Technical Field

[0001] The invention relates to the field of magnetic shielding technology which must be used in extremely weak magnetic field measurement in quantum precision measurement, and in particular to a spliced ​​high-temperature superconducting magnetic shielding device and a combined device. Background Art

[0002] In recent years, the rapid development of quantum precision measurement technology has made the methods of extremely weak magnetic field measurement more diversified. Among them, high-sensitivity magnetic field measurement based on atomic spin effect has become the latest research direction. Among the new ultra-high-sensitivity magnetic field measurement devices, the atomic magnetometer operating in the state without spin exchange relaxation is the most prominent, which can theoretically reach aT (10 -18 However, one of the conditions to achieve a spin-free state is a weak magnetic environment close to zero. High permeability materials are usually used to make magnetic shielding barrels with high shielding performance to effectively isolate the ambient magnetic field. However, the sensitivity of the magnetic field measurement device is limited by magnetic noise, and one of the sources of magnetic noise is the noise of the magnetic shielding barrel itself.

[0003] Generally, due to the hysteresis loss and eddy current loss of soft magnetic materials, the magnetic shielding barrel will generate thermal magnetization noise and Johnson current noise. For soft magnetic materials with both high magnetic permeability and high resistivity, the noise mainly comes from thermal magnetization noise. The noise of the infinite length magnetic shielding barrel δB magn for: , Where μ'(T) and μ''(T) are the real and imaginary parts of the complex magnetic permeability, μ 0 is the magnetic permeability in vacuum, k is the Boltzmann constant, r L is the inner diameter of the shielding barrel, t is the thickness of the shielding barrel, T is the temperature, ω = 2πf, and f is the frequency. For soft magnetic materials with high magnetic permeability and low resistivity, the magnetic noise mainly comes from the Johnson current noise generated by the irregular thermal motion of electrons. For an infinitely long cylindrical magnetic shielding barrel, the magnetic noise δB eddy for: , In the formula, r L is the inner diameter of the shielding barrel, k is the Boltzmann constant, T is the temperature, t is the thickness of the shielding barrel, σ is the conductivity of Permalloy, μ'(T) is the real part of the complex magnetic permeability, and C(μ'(T)) is a constant. Summary of the invention

[0004] The present invention provides a spliced ​​high-temperature superconducting magnetic shielding device and a combined device to at least solve the problem of magnetic noise generated by the magnetic shielding device made of soft magnetic materials that cannot be solved. After combining with the spliced ​​superconducting magnetic shielding, the residual magnetism or magnetic noise can be reduced by at least 1-3 orders of magnitude.

[0005] The technical solution of the present invention is as follows: A spliced ​​high-temperature superconducting magnetic shielding device, characterized in that it includes a spliced ​​magnetic shielding barrel formed by splicing and enclosing a plurality of blocks, wherein the blocks are superconducting blocks sintered from high-temperature superconducting powders, the splicing seams between adjacent blocks are filled with superconducting powders, and the splicing seams between adjacent blocks are sealed by gluing superconducting tapes, and high-temperature superconductivity refers to the liquid nitrogen temperature that produces the superconducting phenomenon being ≥77K.

[0006] The high temperature superconducting powder is yttrium barium copper oxide YBCO or bismuth strontium calcium copper oxide BSCCO.

[0007] An oxygen-free copper cooling belt is attached to the outer surface of the barrel body of the spliced ​​magnetic shielding barrel, and oxygen-free copper cooling plates are provided on the top and bottom end surfaces of the spliced ​​magnetic shielding barrel. The oxygen-free copper cooling belt and the oxygen-free copper cooling plate are both connected to a low-temperature circulating refrigeration system, and the low-temperature circulating refrigeration system is equipped with a buffering vibration isolation structure.

[0008] A working cavity located on a supporting device is arranged on the inner bottom surface of the spliced ​​magnetic shielding barrel, and the working cavity is composed of a heat-insulating material and a non-magnetic radiation screen. Both the working cavity and the spliced ​​magnetic shielding barrel have a transversely penetrating light-through hole and a longitudinally penetrating light-through hole.

[0009] The spliced ​​magnetic shielding barrel is a square structure, and each side is formed by splicing a plurality of blocks.

[0010] The superconducting bulk material satisfies the following expression: , Where χ is the superconductor magnetic susceptibility, M is the magnetization intensity, H is the external magnetic field, μ is the superconductor magnetic permeability, and μ 0 is the magnetic permeability of vacuum.

[0011] A combined magnetic shielding device is characterized by comprising a soft magnetic material magnetic shielding device in which the above-mentioned spliced ​​high-temperature superconducting magnetic shielding device is built.

[0012] The soft magnetic material magnetic shielding device comprises a multi-layer Permalloy shell, a window mirror is arranged on the light-through hole in the middle waist of the outermost Permalloy layer, an outwardly extending structure is arranged below the middle waist of the outermost Permalloy layer, the side of the extending structure is connected to a vacuum pump through a vacuum valve, the side of the extending structure is connected to a composite vacuum gauge, and a support frame is arranged on the inner bottom surface of the multi-layer Permalloy shell, and the support frame supports the bottom of the spliced ​​high-temperature superconducting magnetic shielding device.

[0013] The technical effects of the present invention are as follows: The present invention provides a spliced ​​high-temperature superconducting magnetic shielding device and a combined device, which solves the problem that the shielding performance of the soft magnetic material magnetic shielding is limited by its own magnetic noise and cannot be further improved, and the existing superconducting magnetic shielding is limited by large-scale processes and low-temperature working conditions and cannot pass light. A magnetic shielding device combining a spliced ​​superconducting magnetic shielding and a soft magnetic material magnetic shielding is proposed, which further reduces the magnetic noise of the magnetic shielding system and achieves higher magnetic shielding performance. It is of great significance in creating a zero magnetic environment and improving the sensitivity of ultra-high sensitivity and extremely weak magnetic field measurement devices. The present invention can be applied to quantum sensors that are sensitive to magnetic fields, such as atomic inertial measurement, atomic clocks, and quantum computers. The extremely weak magnetic field and extremely low magnetic noise environment provided by the present invention are suitable for scientific experiments and industrial applications such as quantum precision measurement and atomic magnetometers. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a spliced ​​high-temperature superconducting magnetic shielding combination device of the present invention.

[0015] Figure 2 yes Figure 1 Schematic diagram of the structure of the square spliced ​​superconducting magnetic shielding device.

[0016] The description of the accompanying drawings is as follows: 1-soft magnetic material magnetic shielding device; 2-square spliced ​​superconducting magnetic shielding device; 3-light through hole; 4-window mirror; 5-support frame; 6-oxygen-free copper cooling belt; 7-low-temperature circulation refrigeration system; 8-buffering vibration isolation structure; 9-compound vacuum gauge; 10-vacuum pump; 11-superconducting tape; 12-working chamber; 13-oxygen-free copper cooling plate; 14-vacuum valve. DETAILED DESCRIPTION

[0017] Below is the attached figure ( Figure 1-Figure 2 ) and examples illustrate the present invention.

[0018] Figure 1 It is a structural schematic diagram of a spliced ​​high-temperature superconducting magnetic shielding combination device of the present invention. Figure 2 yes Figure 1 Schematic diagram of the square splicing superconducting magnetic shielding device structure. Figure 1 to Figure 2 As shown, a spliced ​​high-temperature superconducting magnetic shielding device includes a spliced ​​magnetic shielding barrel (for example, Figure 2 The square spliced ​​superconducting magnetic shielding device 2 is a superconducting block material sintered by high-temperature superconducting powder, the splicing seams between adjacent blocks are filled with superconducting powder, and the splicing seams between adjacent blocks are sealed by pasting with superconducting tapes 11. High-temperature superconductivity refers to the liquid nitrogen temperature that produces superconductivity ≥ 77K.

[0019] The high-temperature superconducting powder is yttrium barium copper oxide YBCO or bismuth strontium calcium copper oxide BSCCO. An oxygen-free copper cold conduction belt 6 is attached to the outer surface of the barrel body of the spliced ​​magnetic shielding barrel, and the top and bottom surfaces of the spliced ​​magnetic shielding barrel are both provided with oxygen-free copper cold conduction plates 13. The oxygen-free copper cold conduction belt 6 and the oxygen-free copper cold conduction plate 13 are both connected to a low-temperature circulation refrigeration system 7, and the low-temperature circulation refrigeration system 7 is equipped with a buffer vibration isolation structure 8. A working chamber 12 located on a supporting device is provided on the inner bottom surface of the spliced ​​magnetic shielding barrel, and the working chamber 12 is composed of a heat-insulating material and a non-magnetic radiation screen. The working chamber 12 and the spliced ​​magnetic shielding barrel both have a transversely penetrating light-through hole and a longitudinally penetrating light-through hole. The spliced ​​magnetic shielding barrel is a square structure, and each side is spliced ​​with multiple blocks.

[0020] The superconducting bulk material satisfies the following expression: , Where χ is the superconductor magnetic susceptibility, M is the magnetization intensity, H is the external magnetic field, μ is the superconductor magnetic permeability, and μ 0 is the magnetic permeability of vacuum.

[0021] A combined magnetic shielding device includes a soft magnetic material magnetic shielding device 1 in which the above-mentioned spliced ​​high-temperature superconducting magnetic shielding device is built. The soft magnetic material magnetic shielding device 1 includes a multi-layer permalloy shell, a window mirror 4 is arranged on the light-through hole 3 in the middle waist of the outermost layer of permalloy, and an outward extension structure is provided below the middle waist of the outermost layer of permalloy, the side of the extension structure is connected to a vacuum pump 10 through a vacuum valve 14, and the side of the extension structure is connected to a composite vacuum gauge 9, and a support frame 5 is arranged on the inner bottom surface of the multi-layer permalloy shell, and the support frame 5 supports the bottom of the spliced ​​high-temperature superconducting magnetic shielding device.

[0022] The present invention provides a superconducting magnetic shield and a superconducting tape splicing combined magnetic shielding device, which overcomes the difficulty that the superconducting magnetic shield is limited by the size and low shielding efficiency, and aims to solve the problem that the traditional soft magnetic material magnetic shield cannot further improve the performance due to its own magnetic noise. The combined magnetic shielding device includes components such as soft magnetic material magnetic shielding, square splicing superconducting magnetic shielding body, superconducting tape and low-temperature circulation refrigeration system. The soft magnetic material magnetic shielding shields the external environmental magnetic field, and the superconducting magnetic shielding and superconducting tape reduce the internal remanent magnetism and magnetic noise of the soft magnetic material magnetic shielding, thereby achieving ultra-high magnetic shielding performance. The present invention solves the problem of magnetic noise of soft magnetic materials, proposes a solution for combining soft magnetic material magnetic shielding with superconducting magnetic shielding, and constructs an environment with ultra-low remanent magnetism and magnetic noise. It is suitable for fields such as quantum precision measurement and its application, and improves the sensitivity and performance of quantum precision measurement.

[0023] A spliced ​​superconducting magnetic shield and a combined magnetic shield device, comprising a spliced ​​superconducting magnetic shield composed of a superconducting block sintered from high-temperature superconducting powder, a superconducting tape, and superconducting powder; The high-temperature superconducting powder refers to a material that can produce superconductivity above liquid nitrogen temperature (77K), also known as copper oxide superconductor, including yttrium barium copper oxide YBCO (YBa2Cu3O7), bismuth strontium calcium copper oxide BSCCO (Bi2Sr2Ca2Cu3O10), etc. The combined magnetic shielding device comprises: a magnetic shield made of soft magnetic material, a square spliced ​​superconducting magnetic shielding body, a low-temperature circulation refrigeration system, a vacuum pump, a composite vacuum gauge, a vacuum valve, a light hole, a support frame, a working chamber and a buffer vibration isolation structure.

[0024] The soft magnetic material magnetic shield is made of high magnetic permeability material (magnetic permeability greater than 10000, such as Permalloy, Fe-based amorphous alloy, etc.), and is used as a vacuum shell of the combined magnetic shielding device to shield the external magnetic field. The residual magnetism in the barrel after shielding is about 1nT. It is also used to create a vacuum environment with a vacuum degree of 10 -4 Pa.

[0025] The square spliced ​​superconducting magnetic shielding body is used to shield the magnetic field and magnetic noise inside the soft magnetic material magnetic shielding, and ensure the internal extremely weak magnetic environment; the shielding body is formed by splicing a plurality of square superconducting blocks to form a six-sided closed magnetic shielding body, and the joints are filled by splicing superconducting tapes, superconducting powders, superconducting blocks, etc., to ensure the continuity of the overall structure and the shielding performance.

[0026] The low-temperature circulating refrigeration system is used to provide a low-temperature environment (below the superconducting critical temperature) to ensure that the superconducting magnetic shielding body operates in a superconducting state; it is connected to the magnetic shielding of the outer soft magnetic material through a buffering vibration isolation structure, and the cold energy is transferred to the superconducting magnetic shielding body through a cold plate and a cold belt to ensure that it remains in a superconducting state. The cold plate and the cold belt are made of non-magnetic and high thermal conductivity materials such as oxygen-free copper.

[0027] The vacuum pump and the composite vacuum gauge are connected to the outer magnetic shield through a vacuum valve to extract the gas in the entire device and the working chamber to achieve a vacuum environment to prevent cold loss, while also measuring and controlling the vacuum environment to ensure the stability and reliability of the vacuum environment.

[0028] The vacuum valve is arranged on the device housing and is used to connect the vacuum pump and the compound vacuum gauge, so as to facilitate operation and maintenance.

[0029] The light holes are respectively located on the side walls, upper and lower bottoms of the magnetic shielding shell made of soft magnetic material, the centers of the six surfaces of the spliced ​​superconducting magnetic shielding, and the upper and lower bottoms and side walls of the working cavity. To ensure the passage of light beams, the upper and lower cold plates also have corresponding openings.

[0030] The support frame is used to support the spliced ​​superconducting magnetic shielding body to a required height.

[0031] The working chamber is composed of heat-insulating materials and non-magnetic radiation screens to ensure that the internal temperature is not affected by the external low-temperature environment. The interior is a working area for conducting experiments in an extremely weak magnetic field and extremely low magnetic noise environment.

[0032] The buffer vibration isolation structure is used to alleviate the influence of refrigerator vibration.

[0033] The cold head of the cryogenic refrigerator of the entire device is connected to the cold plates at the upper and lower bottoms of the superconducting magnetic shielding body and the cold plates on the side walls through cold belts; the soft magnetic material magnetic shielding shell, the spliced ​​superconducting magnetic shielding body, and the working chamber are concentrically assembled through light holes, the spliced ​​superconducting magnetic shielding body is placed on a support frame, the bottom of the cold plate is connected to the support frame, and the soft magnetic material magnetic shielding shell is connected to the compound vacuum gauge and the vacuum pump through a vacuum valve.

[0034] A method of using the spliced ​​superconducting magnetic shield and the combined magnetic shield device provides an extremely weak magnetic field and an extremely low magnetic noise environment, which is suitable for scientific experiments and industrial applications such as quantum precision measurement and atomic magnetometers.

[0035] A square spliced ​​superconducting magnetic shield, such as Figure 2 As shown, yttrium barium copper oxide (YBa2Cu3O7, referred to as YBCO) is selected and made into superconducting blocks with a size of 10cm×10cm×5mm through a sintering process. These superconducting blocks will be used to splice to form a square spliced ​​superconducting magnetic shield 2 with a volume of 30cm×30cm×30cm. YBCO superconducting tapes 11 are spliced ​​at the joints, and YBCO superconducting powder is filled at the same time to reduce the influence of leakage magnetic flux at the joints on the shielding performance.

[0036] A combined magnetic shielding device, such as Figure 1As shown, a multi-layer soft magnetic material Permalloy is selected as a soft magnetic material magnetic shield 1, and the outermost Permalloy magnetic shield is used as the device shell. The upper part adopts a cylindrical barrel design with an inner diameter of 450mm and a height of 400mm. The lower part is a runway-shaped cavity as shown in the figure. The two are spliced ​​to form the entire device shell, and the internal multi-layer Permalloy is used to shield the external magnetic field and create a vacuum environment. The upper and lower bottom surfaces of the shell reserve a light hole 3 with a diameter of 30mm, and the side wall reserves a light hole 3 with a diameter of 18mm, which is sealed with a flange and a window mirror 4 to facilitate optical detection and pumping light path. The shell is provided with a plurality of vacuum valves 14 for connecting a vacuum pump 10 and a composite vacuum gauge 9. A buffer vibration isolation structure 8 is installed thereon, which is connected to an external low-temperature circulation refrigeration system 7.

[0037] In this embodiment, the spliced ​​superconducting magnetic shielding is made of yttrium barium copper oxide (YBa2Cu3O7, referred to as YBCO), and is made into a superconducting block material with a size of 10cm×10cm×5mm through a sintering process to form a square closed superconducting magnetic shielding body 2 with a volume of 30cm×30cm×30cm. The six sides are reserved in the center, the upper and lower bottom holes have a diameter of 30mm, and the side wall holes have a diameter of 18mm. YBCO superconducting tapes 11 are pasted at the joints, and YBCO superconducting powder is filled at the same time to reduce the influence of leakage magnetic flux at the joints on the shielding performance.

[0038] In this embodiment, the low-temperature circulation refrigeration system 7 includes an oxygen-free copper cold plate 13, a cold belt 6, and a buffer vibration isolation structure 8. The cold plate 13 is attached to the upper and lower surfaces of the square spliced ​​superconducting magnetic shielding body 2, and the cold belt 6 is attached to the side, which is connected to the cold head of the low-temperature circulation refrigeration system 7 to ensure that the superconducting magnetic shielding body remains in a superconducting state. The low-temperature circulation refrigeration system 7 needs to ensure that the operating temperature is lower than the critical temperature of YBCO (about 92 K or -181°C).

[0039] In this embodiment, the internal support frame 5 is made of epoxy resin material and is placed inside the device to support the square spliced ​​superconducting magnetic shielding body 2, the working cavity 12 and the multi-layer Permalloy magnetic shielding barrel. The bottom of the support frame supporting the superconducting magnetic shielding is connected to the bottom of the inner layer of the soft magnetic material magnetic shielding, and the top is connected to the cold plate at the bottom of the superconducting magnetic shielding body to ensure the stability of the superconducting shielding body.

[0040] In this embodiment, the working chamber 12 is composed of a heat-insulating material and a non-magnetic radiation screen, has a diameter of 180 mm, a height of 250 mm, a light-through hole with a diameter of 18 mm on the side wall, and a light-through hole with a diameter of 30 mm on the upper and lower bottom surfaces. It is located inside the device, and the interior is a working area, providing an experimental environment with an extremely weak magnetic field and extremely low magnetic noise.

[0041] In this embodiment, the working chamber 12 is placed inside the square spliced ​​superconducting magnetic shield 2, and the openings are aligned by supporting the support frame 5. The square spliced ​​superconducting magnetic shield 2 is connected to the cold head of the low-temperature circulation refrigeration system 7 through the cold conduction belt 6 and the cold conduction plate 13. The cold conduction plate is fixed on the inner support frame of the soft magnetic material magnetic shield, and the position of the light hole is confirmed to be aligned to ensure that the light beam can pass smoothly. Connect the vacuum pump 10, the composite vacuum gauge 9 and the vacuum valve 14 to ensure that all interfaces are well sealed, start the vacuum operation, and check whether the vacuum degree meets the requirements. Start the low-temperature circulation refrigeration system 7, gradually reduce the temperature, and make the square spliced ​​superconducting magnetic shield body 2 enter the superconducting state. Monitor the temperature change to ensure that the temperature of each part is uniform, especially to ensure that the temperature is lower than the critical temperature of YBCO (about 92 K or -181 ° C). Use the composite vacuum gauge 9 to monitor the vacuum environment in real time, adjust the working parameters of the vacuum pump 10, and maintain a stable vacuum degree. Test the shielding effect of the device, measure the internal and external magnetic field strength, and confirm the effectiveness of the square spliced ​​superconducting magnetic shield. Adjust the power of the cryogenic cycle refrigeration system 7 according to actual needs to optimize cooling efficiency and stability. Record magnetic field data under different temperature conditions, especially the change of magnetic field when the superconducting magnetic shielding body is cooled from room temperature to the superconducting state, evaluate the performance of spliced ​​superconducting magnetic shielding and combined magnetic shielding devices in reducing magnetic noise, and compare the performance improvement compared with single soft magnetic material magnetic shielding. Theoretically, the remanence that can be achieved by using only multi-layer Permalloy magnetic shielding barrels is about 1nT, and the magnetic noise is 10fT / Hz. 1 / 2 After combining with the spliced ​​superconducting magnetic shielding, the residual magnetism and magnetic noise can be reduced by at least 1-3 orders of magnitude, and the effect is affected by the gaps and processing defects of the spliced ​​superconducting magnetic shielding.

[0042] In order to further improve the sensitivity of extremely weak magnetic field measurement, the design of a high-performance magnetic shielding system is crucial. Since the magnetic noise of soft magnetic materials comes from themselves and cannot be completely eliminated, and superconductors have zero resistance effect and Meissner effect, for high-temperature superconductors, they belong to the second type of superconductors, that is, when the demagnetization factor is zero and the magnetic field intensity is below the critical magnetic field intensity H c1 The following is the Meissner state, c1 and the upper critical magnetic field strength H c2 In the mixed state, c2 The above is a superconductor in normal state.

[0043] The lower critical magnetic field is: , Where Φ 0 is the magnetic flux quantum, λ is the surface penetration depth, and ξ is the coherence length.

[0044] When the external magnetic field H <H c1When the superconductor is in the Meissner state, the magnetic field inside the superconductor is completely expelled, showing complete anti-magnetism. The reverse magnetic field generated by the superconducting current on its surface cancels out the external magnetic field, achieving complete magnetic field shielding.

[0045] In the Meissner state, the magnetic susceptibility χ of the superconductor satisfies: , The corresponding magnetic permeability μ=μ 0 (1+χ)=0, indicating that the superconductor completely repels the external magnetic field H. In addition, the superconducting-normal phase interface energy of the second type superconductor is is a negative value, in H <H c1 When forming magnetic flux lines, it is necessary to overcome energy barriers, thus effectively inhibiting the formation of magnetic flux lines and maintaining the stability of the Meissner state. Since there are no magnetic flux lines inside a superconductor, there is no loss caused by the flow of magnetic flux, and theoretically zero loss can be achieved. Therefore, superconducting magnetic shielding can be used as a new magnetic shielding method, and a new type of superconducting magnetic shielding and combined magnetic shielding device can be designed to achieve an extremely weak magnetic field environment to provide support for the improvement of the sensitivity of extremely weak magnetic field measurements. In addition, the present invention will also be used in quantum sensors that are sensitive to magnetic fields, such as atomic inertial measurement, atomic clocks, and quantum computers.

[0046] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in the field. It is pointed out here that the above description helps those skilled in the art to understand the invention, but does not limit the protection scope of the invention. Any equivalent replacement, modification and / or simplification of the above description without departing from the essence of the invention falls within the protection scope of the invention.

Claims

1. A spliced ​​high-temperature superconducting magnetic shielding device, characterized in that: It comprises a spliced ​​magnetic shielding barrel formed by splicing and enclosing a number of blocks, wherein the blocks are superconducting blocks sintered from high-temperature superconducting powders, the splicing seams between adjacent blocks are filled with superconducting powders, and the splicing seams between adjacent blocks are sealed by gluing superconducting tapes, and high-temperature superconductivity means that the liquid nitrogen temperature that produces the superconducting phenomenon is ≥77K.

2. The spliced ​​high-temperature superconducting magnetic shielding device according to claim 1, characterized in that: The high temperature superconducting powder is yttrium barium copper oxide YBCO or bismuth strontium calcium copper oxide BSCCO.

3. The spliced ​​high-temperature superconducting magnetic shielding device according to claim 1, characterized in that: An oxygen-free copper cooling belt is attached to the outer surface of the barrel body of the spliced ​​magnetic shielding barrel, and oxygen-free copper cooling plates are provided on the top and bottom end surfaces of the spliced ​​magnetic shielding barrel. The oxygen-free copper cooling belt and the oxygen-free copper cooling plate are both connected to a low-temperature circulating refrigeration system, and the low-temperature circulating refrigeration system is equipped with a buffering vibration isolation structure.

4. The spliced ​​high-temperature superconducting magnetic shielding device according to claim 1, characterized in that: A working cavity located on a supporting device is arranged on the inner bottom surface of the spliced ​​magnetic shielding barrel, and the working cavity is composed of a heat-insulating material and a non-magnetic radiation screen. Both the working cavity and the spliced ​​magnetic shielding barrel have a transversely penetrating light-through hole and a longitudinally penetrating light-through hole.

5. The spliced ​​high-temperature superconducting magnetic shielding device according to claim 1, characterized in that: The spliced ​​magnetic shielding barrel is a square structure, and each side is formed by splicing a plurality of blocks.

6. The spliced ​​high-temperature superconducting magnetic shielding device according to claim 1, characterized in that: The superconducting bulk material satisfies the following expression: ， Where χ is the superconductor magnetic susceptibility, M is the magnetization intensity, H is the external magnetic field, μ is the superconductor magnetic permeability, and μ0 is the magnetic permeability in vacuum.

7. A combined magnetic shielding device, characterized in that: The invention comprises a soft magnetic material magnetic shielding device in which the spliced ​​high temperature superconducting magnetic shielding device according to any one of claims 1 to 6 is built.

8. The combined magnetic shielding device according to claim 7, characterized in that: The soft magnetic material magnetic shielding device comprises a multi-layer Permalloy shell, a window mirror is arranged on the light-through hole in the middle waist of the outermost Permalloy layer, an outwardly extending structure is arranged below the middle waist of the outermost Permalloy layer, the side of the extending structure is connected to a vacuum pump through a vacuum valve, the side of the extending structure is connected to a composite vacuum gauge, and a support frame is arranged on the inner bottom surface of the multi-layer Permalloy shell, and the support frame supports the bottom of the spliced ​​high-temperature superconducting magnetic shielding device.

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