Magnetic conductivity measuring device for superconducting material sample

Abstract

The utility model provides a magnetic conductivity measuring device for a superconducting material sample. The magnetic conductivity measuring device comprises a Dewar tank, a sealing assembly, a first heat insulation module, a second heat insulation module, a coil assembly and a magnetic conductivity measuring assembly, a hollow cavity is formed in the Dewar tank, and a superconducting material sample is arranged in the hollow cavity; the sealing assembly covers the opening end of the Dewar tank in a sealing manner; the first heat insulation module is arranged on the sealing assembly and conducts heat insulation on the opening end of the Dewar tank. The second heat insulation module is arranged on the side wall of the Dewar tank and is used for carrying out heat insulation on the side wall of the Dewar tank; the coil assembly is arranged in the hollow cavity of the Dewar tank and surrounds the superconducting material sample; and the magnetic conductivity measuring assembly is electrically connected with the coil assembly. By arranging the first heat insulation module and the second heat insulation module, heat leakage between the external environment and the hollow cavity of the Dewar tank can be effectively reduced, so that the accuracy of a magnetic conductivity test result is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of superconducting test, and in particular relates to a magnetic permeability measuring device for a superconducting material sample. Background Art

[0002] Magnetic permeability (also known as magnetic susceptibility) is a key parameter for characterizing the magnetic behavior of materials and is widely used in a variety of cutting-edge fields, including the study of the magnetic properties of structural materials, the design of magnetic confinement systems, magnetic field shielding analysis, and the development of high-field magnets. Currently, methods for measuring magnetic permeability primarily include vibrating sample magnetometers (VSMs), superconducting quantum interference devices (SQUIDs), and Hall probes. These devices are primarily used in laboratory environments and are often limited to low magnetic fields or cryogenic conditions. However, measuring magnetic permeability at other temperatures, such as room temperature, under the high magnetic fields provided by superconducting magnets (0-14T or even higher) remains a niche technology or difficult to implement in engineering due to challenges such as temperature control, magnetic field interference, and structural design.

[0003] Although there are testing devices in the prior art that keep superconducting magnet samples at a non-low temperature, such as room temperature, and coexist with a strong magnetic field, for example, patent publication number CN222561762U proposes a conduction-cooled superconducting magnet testing device, the design between its dewar tank and the flange used for sealing does not consider the thermal isolation problem under a strong magnetic field, resulting in heat leakage from the external environment. Utility Model Content

[0004] The purpose of the utility model is to solve the problem of heat leakage between the test device and the external environment in the prior art.

[0005] In order to solve the above technical problems, the utility model discloses a magnetic permeability measuring device for a superconducting material sample, comprising: a dewar tank, a sealing assembly, a first thermal insulation module, a second thermal insulation module, a coil assembly and a magnetic permeability measuring assembly; wherein, the dewar tank has a hollow cavity, and the superconducting material sample is placed in the hollow cavity; the sealing cover of the sealing assembly is arranged at the open end of the dewar tank; the first thermal insulation module is arranged at the sealing assembly to insulate the open end of the dewar tank; the second thermal insulation module is arranged at the side wall of the dewar tank to insulate the side wall of the dewar tank; the coil assembly is arranged in the hollow cavity of the dewar tank and surrounds the superconducting material sample; and the magnetic permeability measuring assembly is electrically connected to the coil assembly.

[0006] Using the above technical solution, a sealing cap of the sealing assembly is positioned at the open end of the dewar vessel. A superconducting material sample and a coil assembly surrounding the superconducting material sample are both positioned within the dewar vessel's hollow cavity. The magnetic permeability measurement assembly is electrically connected to the coil assembly. When alternating current is passed through the coil assembly, voltage information of the superconducting material sample is obtained, and the magnetic permeability measurement assembly determines the magnetic permeability of the superconducting material sample based on the voltage information. Furthermore, a first thermal insulation module is positioned on the sealing assembly, and a second thermal insulation module is positioned on the sidewall of the dewar vessel. This effectively reduces heat leakage between the external environment and the dewar vessel's hollow cavity when the dewar vessel's hollow cavity is at a certain temperature (e.g., room temperature) and has a temperature difference with the external environment, maintaining a stable temperature within the dewar vessel's hollow cavity, thereby improving the accuracy of the superconducting material sample measurement results.

[0007] According to another specific embodiment of the present invention, the embodiment of the present invention discloses a magnetic permeability measuring device for a superconducting material sample, wherein the sealing assembly includes a first flange, a second flange and a supporting component, the first flange and the second flange are spaced apart, and the first flange sealing cover is provided at the open end of the Dewar tank, the second flange is farther away from the open end relative to the first flange, the supporting component is located between the first flange and the second flange, and the two ends are fixedly connected to the first flange and the second flange respectively; the supporting component includes a plurality of thermal insulation rods, the plurality of thermal insulation rods are extended between the first flange and the second flange, spaced apart from each other along the height direction of the Dewar tank, and the two ends of each thermal insulation rod are respectively fixed to the first flange and the second flange; the first thermal insulation module includes a middle thermal insulation component and a radiation shield, the middle thermal insulation component is sleeve-shaped, and the two ends are respectively fixed to the second flange and the first flange, covering at least the opening of the Dewar tank in the height direction of the Dewar tank; the radiation shield is fixed to the plurality of thermal insulation rods located on the periphery of the middle thermal insulation component.

[0008] By adopting the above technical solution, by providing an intermediate heat insulating component whose two ends are respectively fixed to the second flange and the first flange and covers at least the opening of the Dewar jar in the height direction of the Dewar jar, the heat conduction between the sealing assembly and the Dewar jar can be reduced. By providing a radiation shield fixed to a plurality of heat insulating support rods located on the periphery of the intermediate heat insulating component, the heat radiation effect of the external environment can be reduced. By providing a plurality of heat insulating support rods located between the first flange and the second flange, extending in the height direction of the Dewar jar at intervals, and having their two ends respectively fixed to the first flange and the second flange, not only can the first flange and the second flange be supported, but the heat conduction between the sealing assembly and the Dewar jar can also be further reduced.

[0009] According to another specific embodiment of the present invention, in the magnetic permeability measuring device for a superconducting material sample disclosed in the embodiment of the present invention, a plurality of thermal insulation support rods are evenly distributed on the first flange; and the radiation protection sheet is formed of an aluminum plate.

[0010] With the above technical solution, multiple insulation rods are evenly distributed on the first flange, achieving uniform insulation. The radiation shielding sheet is formed of aluminum plate. Due to the high thermal radiation reflectivity of aluminum plate, the radiation shielding sheet can reduce the thermal radiation effect of the external environment.

[0011] According to another specific embodiment of the present invention, the embodiment of the present invention discloses a device for measuring the magnetic permeability of a superconducting material sample, wherein the side wall of the Dewar tank is composed of a plurality of coaxial cylindrical walls with different inner diameters, and a side wall cavity is formed between two adjacent cylindrical walls in the wall thickness direction, and each side wall cavity is evacuated or filled with an insulating gas medium; a side wall exhaust port is provided at the top of each side wall cavity, and each side wall exhaust port is connected to one end of an exhaust pipe passing through the sealing assembly, and the other end of the exhaust pipe passes through the sealing assembly and is connected to the outside world.

[0012] Using this technical solution, the sidewalls of the dewar jar form multiple sidewall cavities, each of which is evacuated or filled with a heat-insulating gas medium. This reduces heat convection between the external environment and the hollow cavity of the dewar jar, further insulating the sidewalls of the dewar jar. Furthermore, each sidewall cavity can be evacuated or filled with a heat-insulating gas medium through one end of the exhaust pipe that is connected to the outside world.

[0013] According to another specific embodiment of the present invention, in the magnetic permeability measuring device for a superconducting material sample disclosed in the embodiment of the present invention, each cylindrical wall is formed by winding a metal plate; the second thermal insulation module includes a composite thermal insulation layer attached to at least one side surface of each cylindrical wall; the composite thermal insulation layer is attached to at least one side surface of each cylindrical wall by gluing.

[0014] By adopting the above technical solution, the second insulation module includes a composite insulation layer attached to at least one side surface of each cylindrical wall, which can reduce the heat convection between the external environment and the hollow cavity of the Dewar tank while reducing the heat radiation effect of the external environment.

[0015] According to another specific embodiment of the present invention, in the magnetic permeability measuring device for a superconducting material sample disclosed in the embodiment of the present invention, at least one side surface of each cylindrical wall is further coated with a reflective coating.

[0016] By adopting the above technical solution, at least one side surface of each cylindrical wall is coated with a reflective coating, which can further reduce the heat radiation effect of the external environment.

[0017] According to another specific embodiment of the present invention, in the magnetic permeability measuring device for a superconducting material sample disclosed in the embodiment of the present invention, the cylindrical wall closest to the hollow cavity has a corrugated cross-section.

[0018] With the above technical solution, the cylindrical wall closest to the hollow cavity has a corrugated cross-section, forming a nonlinear heat flow path to further reduce heat conduction and heat radiation.

[0019] According to another specific embodiment of the present invention, the embodiment of the present invention discloses a magnetic permeability measuring device for a superconducting material sample, wherein the superconducting material sample and the coil assembly are arranged in the hollow cavity of a dewar tank through a suspension assembly, one end of the suspension assembly is connected to the superconducting material sample and the coil assembly, and the other end extends along the height direction of the dewar tank and is fixed to the sealing assembly; the coil assembly includes a collection coil and an excitation coil, the collection coil surrounds the superconducting material sample, the excitation coil surrounds the collection coil, and the inner diameter of the excitation coil is larger than the outer diameter of the collection coil.

[0020] Using this technical solution, the suspension assembly secures the superconducting material sample and coil assembly within the hollow chamber of the dewar, preventing contact between the sample and coil assembly and the side and bottom walls of the dewar, thereby ensuring the accuracy of the measured magnetic permeability. The coil assembly includes a collection coil and an excitation coil. The excitation coil receives alternating current, generating an alternating magnetic field. The collection coil senses voltage from the superconducting material sample, which is then used to determine the magnetic permeability of the superconducting material sample.

[0021] According to another specific embodiment of the present invention, the embodiment of the present invention discloses a magnetic permeability measuring device for a superconducting material sample, and the magnetic permeability measuring component includes an AC power supply, a high-speed integrator and an impedance analyzer; the AC power supply is electrically connected to the excitation coil, the high-speed integrator is electrically connected to the acquisition coil, and the impedance analyzer is electrically connected to the high-speed integrator.

[0022] Using the above technical solution, an AC power supply is electrically connected to the excitation coil to generate an alternating magnetic field, the acquisition coil senses the voltage information of the superconducting material sample, a high-speed integrator is electrically connected to the acquisition coil, and the voltage information of the superconducting material sample induced in the acquisition coil is integrated, and an impedance analyzer is electrically connected to the high-speed integrator, and the magnetic permeability of the superconducting material sample is determined based on the voltage information of the superconducting material sample integrated by the high-speed integrator.

[0023] According to another specific embodiment of the present invention, the embodiment of the present invention discloses a magnetic permeability measuring device for a superconducting material sample, and the magnetic permeability measuring device also includes a heater, a temperature sensor and a temperature controller; the heater and the temperature sensor are fixed in the hollow cavity of the Dewar tank, the heater surrounds the coil assembly, the temperature sensor is located on one side of the heater, and the temperature controller is electrically connected to the temperature sensor and the heater, respectively.

[0024] Using the above technical solution, the heater is fixed in the hollow cavity of the Dewar jar, and the temperature controller is electrically connected to the temperature sensor and the heater respectively. The heating efficiency of the heater can be adjusted according to the temperature of the hollow cavity, thereby realizing the temperature control of the hollow cavity of the Dewar jar, thereby providing a test space in a non-low temperature environment (such as a room temperature environment).

[0025] The beneficial effects of the utility model are:

[0026] The utility model provides a magnetic permeability measurement device for a superconducting material sample, comprising: a dewar, a sealing assembly, a first thermal insulation module, a second thermal insulation module, a coil assembly, and a magnetic permeability measurement assembly. The sealing assembly includes a sealing cover disposed at the open end of the dewar, a superconducting material sample and a coil assembly surrounding the superconducting material sample disposed within the dewar's hollow cavity, and the magnetic permeability measurement assembly is electrically connected to the coil assembly. When an alternating current is passed through the coil assembly, voltage information of the superconducting material sample is obtained, and the magnetic permeability measurement assembly determines the magnetic permeability of the superconducting material sample based on the voltage information. Furthermore, the first thermal insulation module is disposed on the sealing assembly, and the second thermal insulation module is disposed on the sidewall of the dewar. When the dewar's hollow cavity is at a certain temperature (e.g., room temperature) and has a temperature difference with the external environment, heat leakage between the external environment and the dewar's hollow cavity can be effectively reduced, maintaining the dewar's hollow cavity at a stable temperature, thereby improving the accuracy of the superconducting material sample measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic structural diagram of a device for measuring the magnetic permeability of a superconducting material sample provided in an embodiment of the present invention;

[0028] Figure 2 A schematic structural diagram of a Dewar tank of a device for measuring the magnetic permeability of a superconducting material sample provided by an embodiment of the present invention;

[0029] Figure 3 A schematic structural diagram of a sealing assembly and a first thermal insulation module of a device for measuring the magnetic permeability of a superconducting material sample provided by an embodiment of the present invention;

[0030] Figure 4 Schematic diagram of the structure of the coil assembly of the magnetic permeability measuring device of the superconducting material sample and the superconducting material sample provided in an embodiment of the present utility model.

[0031] Description of reference numerals:

[0032] 100. Dewar jar; 110. Hollow cavity; 120. Cylindrical wall; 130. Side wall cavity; 131. Side wall exhaust port; 140. Exhaust pipe; 200. Sealing assembly; 210. First flange; 220. Second flange; 230. Support component; 231. Insulation support rod; 300. First insulation module; 310. Middle insulation component; 320. Radiation shield; 400. Second insulation module; 410. Composite insulation layer; 500. Coil assembly; 510. Acquisition coil; 520. Excitation coil; 600. Permeability measurement assembly; 610. AC power supply; 620. High-speed integrator; 630. Impedance analyzer; 700. Superconducting material sample; 800. Suspension assembly; 910. Heater; 920. Temperature sensor; 930. Temperature controller. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0034] The utility model provides a device for measuring the magnetic permeability of a superconducting material sample. Figure 1 As shown, it includes: a Dewar jar 100, a sealing assembly 200, a first thermal insulation module 300, a second thermal insulation module 400, a coil assembly 500 and a magnetic permeability measurement assembly 600.

[0035] Among them, such as Figure 1 As shown, a dewar 100 has a hollow cavity 110 within it, and a superconducting material sample 700 is placed within this cavity. It should be noted that to reduce the impact of heat convection between the hollow cavity 110 of the dewar 100 and the external environment, cavities are formed on the sidewalls and bottom of the dewar 100. These cavities can be evacuated or filled with an insulating gas medium. The superconducting material sample 700 is made from any magnetic material (for example, a superconducting magnet) and has a specific shape and volume.

[0036] It should be noted that the magnetic permeability measurement device can provide a test space in a low-temperature environment or a test space in a non-cryogenic environment (e.g., room temperature) depending on the test requirements. When a low-temperature test space is required, the hollow cavity 110 of the dewar 100 is filled with a cryogenic medium. The cryogenic medium includes, but is not limited to, low-pressure, dry helium or nitrogen. When the temperature is sufficiently low (reaching the stagnation temperature of helium or nitrogen), the helium or nitrogen is in a liquid state. When a non-cryogenic test space is required (e.g., room temperature), the hollow cavity 110 of the dewar 100 can be filled with or without the cryogenic medium. If filled with the cryogenic medium, the helium or nitrogen is in a gaseous state at room temperature.

[0037] In one embodiment of the present invention, Figure 1 and Figure 2 As shown, the side wall of the Dewar jar 100 is composed of multiple layers of coaxial cylindrical walls 120 with different inner diameters. Figure 2 A side wall cavity 130 is formed between two adjacent cylindrical walls 120 (in the X direction), and each side wall cavity 130 is evacuated or filled with a heat-insulating gas medium; a side wall extraction port 131 is provided at the top of each side wall cavity 130, and each side wall extraction port 131 is connected to an exhaust pipe 140 (such as Figure 1 One end of the air extraction pipe 140 is connected to the outside world, and the other end of the air extraction pipe 140 passes through the sealing component 200.

[0038] It should be noted that in this embodiment, the insulating gas medium includes but is not limited to low-pressure dry helium or nitrogen. The side wall cavities 130 can be evacuated or filled with insulating gas medium through the port at the other end of the exhaust pipe 140, so that each side wall cavity 130 forms a buffer air cavity with extremely low thermal conductivity. The number of cylindrical walls 120 can range from 3 to 7, and the number of side wall cavities 130 formed in this case can range from 2 to 6. For example: Figure 2 As shown, if the side wall of the Dewar jar 100 is composed of seven layers of cylindrical walls 120 , six side wall cavities 130 are formed.

[0039] The exhaust pipe 140 is fixedly and sealedly connected to the sealing assembly 200 and the side wall exhaust port 131 , and the connection method includes but is not limited to welding and integral molding.

[0040] Specifically, each cylindrical wall 120 is formed by rolling a metal plate. In a specific embodiment, the metal plate is a stainless steel plate.

[0041] like Figure 1 As shown, the sealing assembly 200 is sealed and disposed at the open end of the Dewar jar 100 .

[0042] Specifically, the fixing connection method of the sealing assembly 200 and the dewar jar 100 includes, but is not limited to, welding, clamping, etc. The sealing assembly 200 can be a flange assembly consisting of at least two flanges, one of which needs to be sealed and disposed at the open end of the dewar jar 100; the sealing assembly 200 can also be a plug-like structure, with one end of the plug inserted into the inner side of the open end of the dewar jar 100 and sealed to the inner side of the side wall of the dewar jar 100. The sealing assembly 200 can also be other structures that can be used to seal openings in the art.

[0043] In one embodiment of the present invention, Figure 3 As shown, the sealing assembly 200 includes a first flange 210 and a second flange 220 spaced apart and a supporting member 230 located between the first flange 210 and the second flange 220. Figure 1As shown, the first flange 210 sealing cover is provided at the opening end of the Dewar jar 100, and the second flange 220 is further away from the opening end relative to the first flange 210, as shown in FIG. Figure 3 As shown, both ends of the support component 230 are fixedly connected to the first flange 210 and the second flange 220 respectively.

[0044] It should be noted that the fixed connection method between the support component 230 and the first flange 210 and the second flange 220 includes but is not limited to threaded connection, clamping, welding, etc.

[0045] In one embodiment of the present invention, Figure 3 As shown, the support member 230 includes a plurality of heat-insulating support rods 231, which are spaced apart from each other along the height direction of the Dewar 100 ( Figure 3 The two ends of each heat-insulating support rod 231 are respectively fixed on the first flange 210 and the second flange 220.

[0046] It should be noted that the insulating rods 231 are made of a material with a thermal insulation effect known in the art, and the number ranges from 4 to 8. The specific number can be selected based on actual conditions. The multiple insulating rods 231 not only provide support for the first flange 210 and the second flange 220, but also reduce heat conduction between the sealing assembly 200 and the Dewar 100. Furthermore, the multiple insulating rods 231 can be evenly distributed or spaced apart on the first flange 210. The specific number of insulating rods 231 can be determined based on the actual insulation and support effects required, and is not specifically limited in this embodiment.

[0047] Specifically, multiple insulating support rods 231 are evenly distributed on the first flange 210. The insulating support rods 231 are formed of a composite material made of glass fiber and epoxy resin. Since the composite material made of glass fiber and epoxy resin has good thermal insulation properties, it is ensured that the heat conduction from the sealing assembly 200 to the Dewar jar 100 can be reduced through the multiple insulating support rods 231. In addition, the multiple insulating support rods 231 are evenly distributed on the first flange 210, which can better reduce the heat conduction from the sealing assembly 200 to the Dewar jar 100.

[0048] like Figure 1 As shown, the first insulation module 300 is disposed on the sealing assembly 200 to insulate the open end of the Dewar jar 100 .

[0049] It should be noted that, in this embodiment, the first insulation module 300 is made of insulation material and covers at least the open end of the Dewar jar 100, thereby reducing the heat conduction between the sealing assembly 200 and the Dewar jar 100 and the heat radiation effect of the external environment. The insulation material can be a composite material made of glass fiber and epoxy resin (referred to as G10).

[0050] In one embodiment of the present invention, Figure 3 As shown, the first insulation module 300 includes a middle insulation component 310 and a radiation shield 320. The middle insulation component 310 is sleeve-shaped, and its two ends are fixed to the second flange 220 and the first flange 210 respectively. Figure 3 the radiation shielding sheet 320 is fixed to a plurality of heat-insulating support rods 231 located on the periphery of the middle heat-insulating member 310 .

[0051] It should be noted that in this embodiment, a portion of the plurality of heat-insulating support rods 231 are located inside the middle heat-insulating component 310, and another portion of the heat-insulating support rods 231 are located outside the middle heat-insulating component 310. In a specific embodiment, the radiation shielding sheet 320 can be arranged along a length direction perpendicular to the heat-insulating support rods 231 ( Figure 3 In another embodiment, the heat insulating rod 231 may be located only on the periphery of the middle heat insulating component 310 and extend in a direction perpendicular to the length direction of the heat insulating rod 231 (Y direction). Figure 3 The number of radiation shielding sheets 320 can be multiple, for example, 3-5, and the multiple radiation shielding sheets 320 can be spaced evenly or unevenly along the length of the insulation rods 231. In another embodiment, the radiation shielding sheets 320 can only cover the outer periphery of the insulation rods 231 outside the central insulation component 310 and extend along the length of the insulation rods 231 to reduce the effect of thermal radiation from the external environment.

[0052] It should be further explained that the fixing connection methods of the middle heat insulation component 310 and the first flange 210 and the second flange 220 include but are not limited to threaded connection, clamping, welding and bonding. The connection methods of the radiation protection sheet 320 and the heat insulation support rod 231 include but are not limited to welding, clamping and bonding.

[0053] Specifically, the intermediate insulation member 310 is a sleeve with a certain wall thickness, formed from a composite material of glass fiber and epoxy resin (G10 for short). Due to the excellent thermal insulation properties of this composite material, the intermediate insulation member 310 reduces heat conduction from the sealing assembly 200 to the Dewar 100. The connection between the intermediate insulation member 310 and the first flange 210 or the second flange 220 is coated with epoxy resin glue, ensuring a sealed connection between the intermediate insulation member 310 and the first flange 210 or the second flange 220. The intermediate insulation member 310 can also be coated with epoxy resin glue at both the connection points with the first flange 210 and the second flange 220. The radiation shielding sheet 320 is formed from an aluminum plate. Due to its high thermal reflectivity, the radiation shielding sheet 320 reduces the effects of external thermal radiation. To improve its thermal reflectivity, the surface of the aluminum plate can be polished.

[0054] like Figure 1 As shown, the second insulation module 400 is disposed on the side wall of the dewar vessel 100 to insulate the side wall of the dewar vessel 100 .

[0055] It should be noted that, in this embodiment, the second insulation module 400 can be fixedly set in the cavity of the side wall of the Dewar tank 100, or can be fixedly set on the inner side of the side wall of the Dewar tank 100, or can be set on the outer side of the side wall of the Dewar tank 100, as long as the insulation of the side wall of the Dewar tank 100 can be achieved.

[0056] In one embodiment of the present invention, Figure 1 and Figure 2 As shown, the second thermal insulation module 400 includes a composite thermal insulation layer 410 attached to at least one side surface of each cylindrical wall 120, and the composite thermal insulation layer 410 includes a gel thermal insulation layer and a reflective film layer stacked together, wherein the gel thermal insulation layer is formed of silica aerogel, and the reflective film layer is composed of alternating layers of aluminum foil and polyester film; the composite thermal insulation layer 410 is attached to at least one side surface of each cylindrical wall 120 by gluing.

[0057] Specifically, a composite thermal insulation layer 410 is affixed to each cylindrical wall 120, significantly enhancing the thermal insulation of the sidewalls of the Dewar 100. The gel insulation layer is formed from silica aerogel, offering excellent thermal insulation properties. The reflective film layer is comprised of alternating layers of aluminum foil and polyester film, exhibiting high thermal radiation reflectivity. The composite thermal insulation layer 410, comprising the stacked gel insulation layer and reflective film layer, reduces heat convection between the external environment and the hollow cavity 110 of the Dewar 100 while also reducing the thermal radiation effects of the external environment, thereby achieving dual-layer shielding against both thermal conduction and radiation. To further enhance the thermal insulation effect, the composite thermal insulation layer 410 is adhered to at least one side of each cylindrical wall 120 using insulating tape. In one embodiment, the insulating tape is polyimide tape.

[0058] In one embodiment of the present invention, at least one side of each cylindrical wall 120 is coated with a reflective coating formed from a titanium dioxide film. This low-reflectivity titanium dioxide film further reduces the effects of external thermal radiation. To ensure reflectivity, the reflective coating must be evenly applied to at least one side of each cylindrical wall 120.

[0059] It should be noted that the composite heat-insulating layer 410 and the reflective coating may be coated on the same side surface of each cylindrical wall 120 , or may be coated on different side surfaces of each cylindrical wall 120 .

[0060] In one embodiment of the present invention, Figure 2 As shown, the cylindrical wall 120 closest to the hollow cavity 110 has a corrugated cross-section. This can form a nonlinear heat flow path, causing the heat flow to decay layer by layer, further reducing heat conduction and heat radiation. If the hollow cavity 110 of the dewar 100 is filled with a cryogenic medium such as helium or nitrogen, the consumption of the cryogenic medium in the dewar 100 can be reduced.

[0061] like Figure 1 As shown, the coil assembly 500 is disposed within the hollow chamber 110 of the dewar 100, surrounding the superconducting material sample 700. The magnetic permeability measurement assembly 600 is electrically connected to the coil assembly 500. When an alternating current is applied to the coil assembly 500, voltage information from the superconducting material sample 700 is obtained. The magnetic permeability measurement assembly 600 can then determine the magnetic permeability of the superconducting material sample 700 based on the voltage information.

[0062] Specifically, such as Figure 4As shown, coil assembly 500 includes a collection coil 510 and an excitation coil 520. Collection coil 510 surrounds superconducting material sample 700, while excitation coil 520 surrounds collection coil 510. The inner diameter of excitation coil 520 is larger than the outer diameter of collection coil 510. When alternating current is applied to excitation coil 520, an alternating magnetic field is generated, and collection coil 510 can collect voltage information induced in superconducting material sample 700.

[0063] It should be noted that, in this embodiment, the acquisition coil 510 and the excitation coil 520 both include a skeleton and a coil, and the coils are wound on the corresponding skeleton. The inner diameter of the skeleton of the excitation coil 520 is larger than the outer diameter of the skeleton of the acquisition coil 510, and the skeleton of the acquisition coil 510 surrounds the superconducting material sample 700.

[0064] In one embodiment of the present invention, the superconducting material sample 700 and the coil assembly 500 are disposed in the hollow cavity 110 of the dewar jar 100 via a suspension assembly 800. One end of the suspension assembly 800 is connected to the superconducting material sample 700 and the coil assembly 500, and the other end is connected along the height direction of the dewar jar 100 ( Figure 1 The Y direction in FIG. 2 extends and is fixed to the sealing assembly 200.

[0065] It should be noted that, in one specific embodiment of the present embodiment, the suspension assembly 800 includes multiple sets of support rods, one end of each set of support rods being used to securely connect the superconducting material sample 700 and the frame of the coil assembly 500. The suspension assembly 800 provides mechanical support to the superconducting material sample 700 and the coil assembly 500, thereby preventing the superconducting material sample 700 and the coil assembly 500 from contacting the side and bottom walls of the Dewar 100, thereby ensuring the accuracy of the measured magnetic permeability.

[0066] In one embodiment of the present invention, Figure 1 As shown, the magnetic permeability measurement assembly 600 includes an AC power supply 610, a high-speed integrator 620 and an impedance analyzer 630; the AC power supply 610 is electrically connected to the excitation coil 520, the high-speed integrator 620 is electrically connected to the acquisition coil 510, and the impedance analyzer 630 is electrically connected to the high-speed integrator 620.

[0067] Specifically, the AC power supply 610 is electrically connected to the excitation coil 520 for providing an AC signal of a certain frequency to the excitation coil 520; the acquisition coil 510 is used to collect voltage information induced on the superconducting material sample 700; the high-speed integrator 620 is electrically connected to the acquisition coil 510 for integrating the voltage collected by the acquisition coil 510 to obtain the integrated voltage; the impedance analyzer 630 is electrically connected to the high-speed integrator 620 for determining the magnetic permeability of the superconducting material sample 700 based on the integrated voltage, thereby realizing the measurement of the magnetic permeability of the superconducting material sample 700, which is also a commonly used method for measuring magnetic permeability in this field.

[0068] In a specific embodiment, Figure 1 As shown, the magnetic permeability measurement assembly 600 also includes a computer 640, which is electrically connected to the impedance analyzer 630 and is used to obtain, store, and display the magnetic permeability of the superconducting material sample 700 for easy reading and display. This allows for automatic reading and storage of the corresponding measurement data, preventing data loss in the event of an unexpected power outage or other event. Furthermore, the computer 640 can display the measured magnetic permeability, facilitating timely monitoring of the measurement results.

[0069] In one embodiment of the present invention, Figure 1 As shown, the magnetic permeability measuring device further includes a heater 910, a temperature sensor 920 and a temperature controller 930; the heater 910 and the temperature sensor 920 are fixed in the hollow cavity 110 of the Dewar tank 100, the heater 910 surrounds the coil assembly 500, the temperature sensor 920 is located on one side of the heater 910, and the temperature controller 930 is electrically connected to the temperature sensor 920 and the heater 910 respectively.

[0070] Specifically, the temperature sensor 920 is fixed in the hollow cavity 110 of the Dewar tank 100, and is used to obtain temperature information of the hollow cavity 110 of the Dewar tank 100 (actually voltage information corresponding to the temperature). The temperature controller 930 is electrically connected to the temperature sensor 920 and the heater 910 respectively, and is used to obtain temperature information based on the voltage information. The temperature controller 930 can have a built-in PID program to control the heating efficiency of the heater 910 based on the temperature information, thereby achieving temperature control of the hollow cavity 110 of the Dewar tank 100, thereby providing a test space in a non-low temperature environment (such as a room temperature environment), thereby achieving the measurement of the magnetic permeability of the superconducting material sample 700 in a non-low temperature environment (such as a room temperature environment).

[0071] It should be noted that the temperature sensor 920 can be bonded to the inner side of the side wall of the Dewar jar 100. In order to improve accuracy, the number of the temperature sensor 920 can also be set to multiple. The bonding material can specifically be epoxy resin glue. The heater 910 can specifically be a heating coil, which can be fixed to the inner side of the side wall of the Dewar jar 100 and wound around the outer periphery of the coil assembly 500. It can also be fixed by the above-mentioned suspension assembly 800. If it is bonded, the bonding material can be epoxy resin glue, specifically STAYCAST 2850 FT epoxy resin glue. In addition, if it is necessary to maintain a low-temperature test space, the heater 910 is not enabled.

[0072] The magnetic permeability measuring device for a superconducting material sample provided by the present invention is provided with a first thermal insulation module 300 on a sealing assembly 200 whose sealing cover is provided at the open end of a dewar jar 100, and a second thermal insulation module 400 is provided on the side wall of the dewar jar 100. In this way, when the hollow cavity 110 of the dewar jar 100 is at a certain temperature state (for example, at room temperature) and there is a temperature difference with the external environment, heat leakage between the external environment and the hollow cavity 110 of the dewar jar 100 can be effectively reduced, so that the hollow cavity 110 of the dewar jar 100 is in a stable temperature state. Furthermore, since the superconducting material sample 700 and the coil assembly 500 surrounding the superconducting material sample 700 are both arranged in the hollow cavity 110 of the Dewar tank 100, the magnetic permeability measurement assembly 600 is electrically connected to the coil assembly 500; after the coil assembly 500 is passed through alternating current, the voltage information of the superconducting material sample 700 can be obtained, and the magnetic permeability measurement assembly 600 can determine the magnetic permeability of the superconducting material sample 700 based on the voltage information, which not only realizes the magnetic permeability measurement of the superconducting material sample 700, but also improves the accuracy of the measurement result because the superconducting material sample 700 is in a stable temperature measurement environment.

[0073] It should be noted that, in addition to the implementation methods of the present invention described in the above-mentioned specific embodiments, those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this utility model are limited to this implementation method. On the contrary, the purpose of introducing the utility model in conjunction with the implementation method is to cover other options or modifications that may be extended based on the claims of the present utility model. In order to provide an in-depth understanding of the present utility model, the following description will contain many specific details. The present utility model can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present utility model, some specific details will be omitted in the description. It should be noted that, in the absence of conflict, the embodiments of the present utility model and the features in the embodiments can be combined with each other.

[0074] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0075] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as a limitation on the utility model.

[0076] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0077] In the description of this embodiment, it should be noted that, unless otherwise specified or limited, the terms "disposed," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections via an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of these terms in this embodiment based on their specific circumstances.

[0078] Although the present invention has been illustrated and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that the above description is provided to further illustrate the present invention in conjunction with specific embodiments, and that the present invention should not be construed as being limited to these descriptions. Those skilled in the art may make various changes in form and detail, including simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A device for measuring the magnetic permeability of a superconducting material sample, characterized in that: include: Dewar tank, sealing assembly, first thermal insulation module, second thermal insulation module, coil assembly and magnetic permeability measurement assembly; The Dewar tank has a hollow cavity, and the superconducting material sample is placed in the hollow cavity; The sealing cover of the sealing assembly is arranged at the opening end of the Dewar tank; The first heat insulation module is provided on the sealing assembly to insulate the open end of the Dewar tank; The second heat insulation module is provided on the side wall of the dewar tank to insulate the side wall of the dewar tank; The coil assembly is disposed in the hollow cavity of the Dewar tank and surrounds the superconducting material sample; The magnetic permeability measurement component is electrically connected to the coil component.

2. The magnetic permeability measuring device for a superconducting material sample according to claim 1, wherein: The sealing assembly includes a first flange, a second flange, and a supporting component. The first flange and the second flange are spaced apart, and the first flange sealing cover is provided at the open end of the Dewar vessel. The second flange is further away from the open end than the first flange. The supporting component is located between the first flange and the second flange, and its two ends are fixedly connected to the first flange and the second flange respectively. The support member includes a plurality of heat-insulating support rods, which are arranged between the first flange and the second flange and extend along the height direction of the dewar vessel at intervals, and each end of the heat-insulating support rod is fixed to the first flange and the second flange respectively; The first thermal insulation module includes a middle thermal insulation component and a radiation shield. The middle thermal insulation component is sleeve-shaped, with both ends respectively fixed to the second flange and the first flange, and covers at least the opening of the Dewar tank in the height direction of the Dewar tank; the radiation shield is fixed to a plurality of the thermal insulation support rods located on the periphery of the middle thermal insulation component.

3. The magnetic permeability measuring device for a superconducting material sample according to claim 2, wherein: A plurality of heat-insulating support rods are evenly distributed on the first flange; and the radiation protection sheet is formed of an aluminum plate.

4. The magnetic permeability measuring device for a superconducting material sample according to claim 3, wherein: The side wall of the Dewar tank is composed of multiple layers of coaxial cylindrical walls with different inner diameters. A side wall cavity is formed between two adjacent cylindrical walls in the wall thickness direction. Each side wall cavity is evacuated or filled with an insulating gas medium. A side wall extraction port is provided at the top of each side wall cavity, and each side wall extraction port is communicated with one end of an exhaust pipe running through the sealing component, and the other end of the exhaust pipe runs through the sealing component and is communicated with the outside world.

5. The magnetic permeability measuring device for a superconducting material sample according to claim 4, characterized in that: Each of the cylindrical walls is formed by winding a metal plate; The second thermal insulation module includes a composite thermal insulation layer attached to at least one side surface of each of the cylindrical walls; The composite heat-insulating layer is adhered to at least one side surface of each cylindrical wall by gluing.

6. The magnetic permeability measuring device for a superconducting material sample according to claim 5, characterized in that: At least one side surface of each cylindrical wall is also coated with a reflective coating.

7. The magnetic permeability measuring device for a superconducting material sample according to claim 6, wherein: The cylindrical wall closest to the hollow cavity has a corrugated cross-section.

8. The magnetic permeability measuring device for a superconducting material sample according to any one of claims 1 to 7, characterized in that: The superconducting material sample and the coil assembly are arranged in the hollow cavity of the dewar tank through a suspension assembly, one end of the suspension assembly is connected to the superconducting material sample and the coil assembly, and the other end extends along the height direction of the dewar tank and is fixed to the sealing assembly; The coil assembly includes a collection coil and an excitation coil. The collection coil surrounds the superconducting material sample. The excitation coil surrounds the collection coil, and an inner diameter of the excitation coil is greater than an outer diameter of the collection coil.

9. The magnetic permeability measuring device for a superconducting material sample according to claim 8, wherein: The magnetic permeability measurement component includes an AC power supply, a high-speed integrator and an impedance analyzer; The AC power supply is electrically connected to the excitation coil, the high-speed integrator is electrically connected to the acquisition coil, and the impedance analyzer is electrically connected to the high-speed integrator.

10. The magnetic permeability measuring device for a superconducting material sample according to any one of claims 1 to 7, characterized in that: The magnetic permeability measuring device also includes a heater, a temperature sensor and a temperature controller; The heater and the temperature sensor are fixed in the hollow cavity of the Dewar tank. The heater surrounds the coil assembly. The temperature sensor is located on one side of the heater. The temperature controller is electrically connected to the temperature sensor and the heater respectively.

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