High-temperature superconducting strip performance testing method and device capable of realizing rapid sample replacement

Abstract

The invention discloses a high-temperature superconducting strip performance test method capable of realizing rapid sample change, which comprises the following steps: S1, placing a first sample rod above a transition cabin, and vacuumizing the interior of a Dewar and the space above the transition cabin; s2, enabling the sample rod to extend into the cold shield, enabling the cold conduction column of the sample groove to be tightly connected with the copper base, and enabling the conductive pin of the sample rod to be tightly contacted with the current lead; s3, starting a refrigerator to cool the interior of the whole device; s4, after the performance of the to-be-tested sample is tested, taking out the sample rod; s5, a next sample rod is placed above the transition cabin, the space above the transition cabin is vacuumized, the sample rod extends into the cold shield, the sample groove cold conduction column is tightly connected with the copper base, the sample rod conductive pin is tightly contacted with the current lead, and rapid sample replacement is completed; s6, performing performance test on the to-be-tested sample, and taking out the sample rod after the performance test is completed; and S7, repeating the steps S5-S6. According to the invention, the test efficiency, the operation convenience and the test precision are comprehensively improved.

Description

Technical Field

[0001] This application belongs to the field of superconducting material testing technology, specifically relating to a method and apparatus for testing the performance of high-temperature superconducting tapes that enables rapid sample changing. Background Technology

[0002] High-temperature superconducting (HTS) tapes, especially second-generation REBCO tapes, have shown great promise for applications in sustainable energy (wind turbines), power infrastructure (transformers), medical equipment (MRI), and large scientific facilities (particle accelerators, nuclear fusion devices) due to their superior current-carrying capacity under high fields. The material's properties, especially the critical current density, are strongly dependent on temperature, magnetic field, and magnetic field direction. Therefore, accurate characterization of the tapes under multi-physics conditions (low temperature, strong magnetic field, variable angle) simulating actual operating conditions is a crucial step in material development, quality control, and device design. The Ic of a superconducting wire is determined by temperature (T), magnetic field strength (H), and magnetic field angle (H). The three-dimensional function (Ic(T,H,)) Measuring only one or two aspects cannot fully reveal the performance boundaries of a material. Especially for commercial second-generation YBCO coated conductors, the angle dependence of samples from different manufacturers and batches varies significantly. Full-angle measurement can provide manufacturers with a complete "portrait" of product performance and also provide a unified and comprehensive evaluation basis for the selection and comparison of conductors from different brands.

[0003] Currently, while commercially available high-performance high-temperature superconducting testing devices can achieve relatively accurate measurements, significant technical bottlenecks exist in sample replacement, severely limiting testing efficiency, especially in applications requiring extensive sample testing to study the performance of high-temperature superconducting tapes. The drawbacks of existing technologies are mainly reflected in the following aspects: The sample change process is cumbersome and extremely time-consuming: each sample change requires removing the entire probe or Dewar from the magnet and allowing it to recover from a low temperature (e.g., 4.2K or 77K) to room temperature. Subsequently, a complex sealing structure needs to be opened, the old sample manually disassembled, and the new sample installed. This process typically takes several hours, and is followed by a lengthy Dewar vacuuming and recooling process. The total time for a single Dewar vacuuming and cooling cycle is usually 1-2 days, resulting in a very lengthy testing process and extremely low equipment utilization.

[0004] The operation is complex and requires highly skilled personnel: The cumbersome sample change operation needs to be completed by experienced professionals, which not only increases labor costs, but also makes it difficult to promote the technology in scenarios such as industrial quality inspection that require fast and standardized operations.

[0005] Disrupting the cryogenic environment and increasing operating costs: Repeated heating and cooling cycles consume large amounts of cryogenic liquids (such as liquid helium or liquid nitrogen), greatly increasing the economic and time costs of testing. Summary of the Invention

[0006] The purpose of this invention is to provide a method and device for testing the performance of high-temperature superconducting tapes that enables rapid sample changing. Through multi-dimensional structural innovation and technological optimization, this invention achieves a comprehensive improvement in testing efficiency, ease of operation, and testing accuracy.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for testing the performance of high-temperature superconducting tapes that enables rapid sample changing includes the following steps: S1, place the first sample rod containing the sample to be tested above the transition chamber, and evacuate the space inside the Dewar and above the transition chamber. S2, insert the sample rod into the cold screen, so that the sample groove cold guide column is tightly connected to the copper base, and the conductive pin of the sample rod is in close contact with the current lead; S3, start the refrigeration unit to cool the entire internal part of the device, and keep the temperature at the operating temperature after it is reduced to the operating temperature. S4. Perform voltage and current tests, temperature tests, magnetic field strength tests, and magnetic field angle tests on the sample to be tested. After the performance tests are completed, lift the sample rod to the top of the transition chamber, close the valve, and take it out. S5, place the next sample rod above the transition chamber, evacuate the space above the transition chamber, insert the sample rod into the cold screen, make the sample groove cold conductive column tightly connected to the copper base, and make the conductive pin of the sample rod in close contact with the current lead to complete the rapid sample change. S6, perform performance testing on the sample to be tested. After completion, lift the sample rod to the top of the transition chamber, close the valve, and remove it. S7, repeat S5-S6 to complete rapid sample switching and performance testing for multiple samples.

[0008] Preferably, the specific steps of S1 are as follows: S101, close the vacuum valve of the transition chamber, insert the sample rod containing the sample to be tested into the space above the transition chamber, seal the cover flange of the sample rod and the flange of the transition chamber, and tighten the knurled nut to form a sealed space above the transition chamber. S102, open the inflation valve and exhaust valve below the transition chamber to evacuate the inside of the Dewar, and at the same time open the inflation valve and exhaust valve above the transition chamber to evacuate the space above the transition chamber.

[0009] Preferably, the specific steps of S2 are as follows: S201, open the vacuum valve of the transition chamber, loosen the knurled nut of the sample rod, insert the sample rod into the cold screen and insert the sample groove cooling column into the groove of the copper base until it can no longer move downwards; S202, rotate the sample rod until it can no longer be rotated, so that the conductive pin of the sample rod is in close contact with the groove structure of the current lead, and finally tighten the knurled nut to fix the sample rod.

[0010] Preferably, in step S3, the refrigerator uses a two-stage cooling system with a cold shield to conduct cold energy and isolate external heat radiation, while the second-stage cold head uses a copper base to conduct cold energy, thereby achieving uniform cooling of the high-temperature superconducting tape sample to be tested.

[0011] A high-temperature superconducting tape performance testing device enabling rapid sample change is disclosed, comprising a sample rod, a transition chamber, a cryostat, current leads, a copper base, a Dewar flask, a cold shield, and a high-temperature superconducting coil. The Dewar flask serves as the main testing chamber, creating a low-temperature vacuum testing environment. The transition chamber is connected to the Dewar flask. The cold shield, copper base, and current leads are all located inside the Dewar flask. The current leads pass through the upper plate of the cold shield and connect to the upper plate of the Dewar flask. The copper base is connected to the upper plate of the cold shield. The cryostat is connected to the cold shield and copper base to achieve staged cooling. The high-temperature superconducting coil is positioned outside the cold shield. The sample rod, containing the high-temperature superconducting tape sample to be tested, extends through the transition chamber into the Dewar flask, and engages with the copper base for positioning and with the current leads for conductivity, thus completing the performance test.

[0012] Preferably, the sample rod has a hollow structure with an aviation plug at the top. From top to bottom, the rod body is provided with a knurled nut, a cover flange, and a sample rotating rod. The lower end of the rod body is provided with a sample rod conductive pin and a sample groove cooling column. The aviation plug is connected to a voltage lead, which passes through the hollow interior of the sample rod and is connected to both ends of the sample rotating rod.

[0013] Preferably, a hard superconducting strip is attached to both the conductive pin of the sample rod and the conductive post of the current lead, and the conductive pin of the sample rod is designed with a staggered arrangement.

[0014] Preferably, the sample tank cooling column is equipped with a Hall sensor and a thermometer.

[0015] Preferably, the refrigerator is a two-stage cooling structure with a primary cooling head connected to the upper plate of the cooling screen, and the secondary cooling head connected to the copper base.

[0016] Preferably, the copper base includes a bottom disc-shaped structure, the center of which is provided with a cylindrical boss with a groove, and the surface of the cylindrical boss is provided with an insulating layer.

[0017] The beneficial effects of this invention are as follows: (1) The device is equipped with a dedicated transition chamber, which greatly improves the efficiency of multi-sample testing. The device innovatively adds an independent transition chamber structure, which can complete the sample replacement operation without damaging the low temperature vacuum environment of the main test chamber. This design completely solves the cumbersome process of reheating, breaking the vacuum, and then cooling and vacuuming again when changing samples in traditional test devices. It eliminates the 1-2 day cooling and Dewar vacuuming steps in traditional sample replacement, and significantly shortens the testing interval of multiple batches of samples. At the same time, the sample replacement operation process is simple and easy to understand, and there is no need to carry out professional skills training for staff, which can effectively reduce labor costs and operating threshold.

[0018] (2) Integrated sample rod design + external high-temperature superconducting coil to realize flexible testing under multiple magnetic field conditions. The sample rod of the device adopts an integrated functional design, which has the dual functions of sample fixation and superconducting tape torsion positioning. It can accurately control the angle between the tape and the magnetic field to meet the sample posture requirements of different testing conditions. At the same time, a high-temperature superconducting coil is arranged outside the cold screen. By adjusting the excitation parameters of the coil, a gradient adjustable magnetic field environment can be flexibly constructed, thereby realizing the systematic testing of the critical current performance of superconducting tape under different magnetic field strengths and magnetic field angles.

[0019] (3) Superconducting tape current leads + liquid helium-free conduction cooling technology ensures test accuracy and safety. The current lead part abandons the traditional metal conductor solution and uses high-temperature superconducting tape as the conductive medium. By utilizing the zero resistance characteristic in the superconducting state, the Joule heat generated by the current lead is minimized, avoiding interference with the low-temperature test environment due to lead heating, thereby effectively eliminating experimental errors and improving the accuracy of critical current test data. In addition, the device adopts liquid helium-free conduction cooling technology, using a closed-loop refrigerator to directly cool the test system. This not only significantly reduces the experimental costs of liquid helium procurement, storage and recycling, but also fundamentally avoids the safety risks caused by liquid helium leakage, significantly improving the stability and safety of the device operation. Attached Figure Description

[0020] Figure 1 This is a flowchart of the method of the present invention.

[0021] Figure 2 This is a schematic diagram of a high-temperature superconducting tape performance testing device.

[0022] Figure 3 This is a detailed view of the sample rod.

[0023] Figure 4 This is a schematic diagram of the transition chamber during testing and sample changing.

[0024] Figure 5 This is a schematic diagram of the current loop during testing.

[0025] In the diagram: 1. Sample rod; 2. Transition chamber; 3. Refrigerator; 4. Current lead; 5. Copper base; 6. Dewar; 7. Cold shield; 8. High-temperature superconducting coil; 11. Aviation plug; 12. Knurled nut; 13. Cover flange; 14. Sample rotating rod; 15. Conductive pin of sample rod; 16. Cooling column of sample slot; 21. Vacuum valve. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0027] like Figure 1 As shown, a method for testing the performance of high-temperature superconducting tapes that enables rapid sample changing includes the following steps: S1, place the first sample rod 1 containing the sample to be tested above the transition chamber 2, and evacuate the space inside the Dewar 6 and above the transition chamber.

[0028] S101, Initial installation of the sample rod: Close the vacuum valve 21 of the transition chamber 2, insert the sample rod 1 containing the sample to be tested into the space above the transition chamber 2, seal the cover flange 13 on the sample rod 1 with the flange of the transition chamber 2, and tighten the knurled nut 12 to form a sealed space above the transition chamber 2.

[0029] Before testing, a sample rod to be tested is prepared. In order to achieve rapid sample change, multiple sample rods are generally prepared. After the test of the previous sample is completed, the sample rod of the second sample to be tested can be placed in the test system immediately.

[0030] The vacuum valve 21 of the transition chamber 2 remains closed. The first sample rod 1, which is pre-cooled and contains the sample to be tested, is inserted into the space above the transition chamber 2. The cover flange 13 on the sample rod 1 is sealed to the flange of the transition chamber 2. The knurled nut 12 on the sample rod 1 is tightened to form a sealed space above the transition chamber 2.

[0031] S102, Vacuum preparation: Open the inflation valve and exhaust valve at the bottom of the transition chamber 2 to evacuate the inside of the Dewar 6; at the same time, open the inflation valve and exhaust valve at the top of the transition chamber 2 to evacuate the space above the transition chamber where part of the sample rod 1 has been inserted.

[0032] S2, insert the sample rod 1 into the cold screen 7, so that the sample groove cooling column 16 is tightly connected to the copper base 5, and the conductive pin 15 of the sample rod is in close contact with the current lead 4.

[0033] S201, after the upper and lower sealed spaces of the transition chamber 2 are both vacuumed, open the vacuum valve 21 of the transition chamber 2, slightly loosen the knurled nut 12 of the sample rod 1 to ensure that the sample rod 1 can move up and down in the sealed state, insert the sample rod 1 into the cold screen 7 and insert the sample groove cooling column 16 into the groove of the copper base 5 until it can no longer move down, which means that the sample groove cooling column 16 is tightly connected to the copper base 5.

[0034] S202, rotate the sample rod 1 at a certain angle until it can no longer be rotated, which means that the conductive pin 15 of the sample rod is in close contact with the groove structure of the conductive post of the current lead 4. At this time, tighten the loose knurled nut 12 to keep the sample rod 1 fixed.

[0035] S3: Start the refrigeration unit to cool the entire internal temperature of the device, and then maintain the temperature at the operating temperature.

[0036] Start the refrigerator 3. The refrigerator 3 uses a two-stage cold head for staged cooling. The first stage cold head is a cold screen that conducts cold energy to isolate external heat radiation, and the second stage cold head is a copper base that conducts cold energy to achieve uniform cooling of the high-temperature superconducting tape sample to be tested.

[0037] S4. Perform voltage and current tests, temperature tests, magnetic field strength tests, and magnetic field angle tests on the sample to be tested. After the performance tests are completed, lift the sample rod to the top of the transition chamber, close the valve, and take it out.

[0038] S401, Voltage and Current Test: Apply current to the current lead and gradually increase the current, monitor the voltage drop at the sample end, and record the critical current Ic when the electric field strength reaches 1μV / cm. Fit the voltage and current relationship VI.

[0039] Turn on the programmable DC power supply connected to the current leads at both ends of the sample under test, and energize the positive and negative terminals to form a current loop. First, apply a small current and observe the voltage change displayed by the digital multimeter connected in parallel across the sample to ensure that the circuit is complete. Then, gradually increase the output current of the programmable DC power supply through software control, while the digital multimeter synchronously acquires the voltage signal across the sample until a specific voltage criterion is reached (usually defined as an electric field strength of 1 μV / cm). The current at this point is defined as the critical current Ic.

[0040] The entire system automatically records real-time current and voltage data through data acquisition software and automatically saves the measurement results as data files. The software can automatically fit the acquired current-voltage data according to a power-law relationship. The resulting voltage-current (VI) relationship is typically modeled using the following power-law form: In the formula, Vc is the set voltage criterion, and the critical current Ic and the power exponent n need to be determined by power-law fitting of the data segment near Ic.

[0041] S402, Temperature Test: Adjust the test circuit current to the set value, change the sample temperature through the temperature control system, collect voltage and temperature data simultaneously, record the change of critical current with temperature, fit the voltage-temperature VT and critical current-temperature Ic-T characteristic curves, and analyze the influence of temperature on the sample's electrical properties.

[0042] Keep the test circuit powered on, adjust the current to the set value and keep it stable; continuously change the ambient temperature of the sample through the temperature control system, and heat up and down at a stable rate within the set temperature range. After the system reaches thermal equilibrium at each temperature point, monitor and record the sample terminal voltage, real-time temperature and circuit electrical parameters simultaneously; repeat the critical current test at different temperatures to obtain the evolution law of critical current Ic with temperature; the data acquisition system automatically saves experimental data such as voltage, temperature and current, and fits the measurement results to obtain voltage-temperature VT and critical current-temperature Ic-T characteristic curves.

[0043] S403, Magnetic Field Strength Test: Keeping other experimental conditions consistent with S402, the magnetic field strength applied to the sample is gradually changed by adjusting the power supply current of the high-temperature superconducting coil 8. Under each set magnetic field strength, after the system stabilizes, the critical current, voltage, and corresponding magnetic field parameters of the sample are tested and recorded. The current of the high-temperature superconducting coil 8 is gradually increased to enhance the magnetic field strength, and the above test is repeated to obtain the variation law of the critical current Ic with the magnetic field strength B. The experimental data such as voltage, current, and magnetic field strength are automatically saved by the data acquisition system, and the voltage-magnetic field strength VB and critical current-magnetic field strength Ic-B characteristic curves are fitted to analyze the influence of the applied magnetic field on the critical current and electrical properties of the high-temperature superconducting tape.

[0044] S404, Magnetic Field Angle Test: By quickly replacing sample rod 1 with different preset angles, and fixing test conditions such as temperature and current, electrical parameters such as sample voltage V and critical current Ic are simultaneously collected at each angle. The data is recorded and fitted to the critical current-magnetic field angle Ic- Characteristic curves.

[0045] By fixing core test conditions such as test temperature and loop current, and maintaining the test circuit continuity and stability, the relative incident angle between the magnetic field and the sample is precisely changed by quickly replacing sample rods with different preset angles. After the sample state stabilizes at each angle, the sample terminal voltage, critical current Ic, and related electrical parameters are monitored and collected simultaneously at the corresponding magnetic field angle, and the changes in electrical performance with the magnetic field angle are fully recorded. The data acquisition system automatically retains various measured data, and the data is regularized and fitted to plot the critical current-angle Ic- By analyzing the characteristic curves, we can gain a deeper understanding of the influence of the magnetic field angle on the electrical properties of the sample and clarify the anisotropic characteristics of the sample's electrical properties.

[0046] After the test is completed, raise the sample rod 1 above the transition chamber 2, close the vacuum valve 21, and then remove it.

[0047] S5, place the next sample rod 1 above the transition chamber 2, evacuate the space above the transition chamber, extend the sample rod into the cold screen, make the sample groove cooling column 16 tightly connected to the copper base 5, and make the conductive pin 15 of the sample rod in close contact with the current lead 4, thus completing the rapid sample change.

[0048] S501, close the vacuum valve 21 of the transition chamber 2, insert the sample rod 1 containing the sample to be tested into the space above the transition chamber 2, seal the cover flange 13 of the sample rod 1 and the flange of the transition chamber 2, and tighten the knurled nut 12 to form a sealed space above the transition chamber 2. Open the inflation valve and exhaust valve above the transition chamber 2 to evacuate the space above the transition chamber 2.

[0049] S502, insert the sample rod 1 into the cold screen 7, so that the sample groove cooling column 16 is tightly connected to the copper base 5, and the conductive pin 15 of the sample rod is in close contact with the current lead 4.

[0050] Sample rod assembly: After the upper and lower sealed spaces of the transition chamber 2 are both vacuumed, open the vacuum valve 21 of the transition chamber 2, slightly loosen the knurled nut 12 of the sample rod 1 to ensure that the sample rod 1 can move up and down in the sealed state, insert it into the cold screen 7 and insert it into the groove of the copper base 5. If it can no longer move down, it means that the sample groove cooling column 16 is tightly connected to the copper base 5. Then, rotate the sample rod 1 at a certain angle until it can no longer rotate, which means that the conductive pin 15 of the sample rod is in close contact with the groove structure of the conductive column of the current lead 4. At this time, tighten the loose knurled nut to keep the sample rod 1 fixed.

[0051] S6, perform performance testing on the sample to be tested. After completion, lift the sample rod to the top of the transition chamber, close the valve, and remove it.

[0052] Voltage, current, temperature, and magnetic field angle tests are performed on the sample to be tested. The test steps have been described in S4 and will not be described in detail here.

[0053] S7, repeat S5-S6 to complete rapid sample switching and performance testing for multiple samples.

[0054] like Figures 2-5As shown, a high-temperature superconducting tape performance testing device capable of rapid sample changing includes a sample rod 1, a transition chamber 2, a refrigerator 3, a current lead 4, a copper base 5, a Dewar 6, a cold shield 7, and a high-temperature superconducting coil 8. The Dewar 6 serves as the main testing chamber, creating a low-temperature vacuum testing environment. The transition chamber 2 is connected to the Dewar 6. The cold shield 7, copper base 5, and current lead 4 are all located inside the Dewar 6. The current lead 4 passes through the upper plate of the cold shield 7 and is securely connected to the upper plate of the Dewar 6. The copper base 5 is also securely connected to the upper plate of the cold shield 7. The refrigerator 3 is connected to the cold shield 7 and the copper base 5 to achieve staged cooling. The high-temperature superconducting coil 8 is arranged outside the cold shield 7. The sample rod 1, containing the high-temperature superconducting tape sample to be tested, extends through the transition chamber 2 into the Dewar 6, and is positioned and engaged with the copper base 5 and conductively engaged with the current lead 4 to complete the performance test.

[0055] Detailed image of sample rod 1 is shown below. Figure 2 As shown, the sample rod 1 has a hollow structure with an aviation plug 11 welded to its top. From top to bottom, the rod body is provided with a knurled nut 12, a cover flange 13 and a sample rotating rod 14. The lower end of the rod body is provided with a sample rod conductive pin 15 and a sample groove cooling column 16.

[0056] The aviation connector 11 connects to the voltage lead for measuring voltage. The voltage lead passes through the hollow interior of the sample rod 1 and is welded to both ends of the sample rotating rod 14. The knurled nut 12 is used to achieve a complete seal between the cover flange 13 and the transition chamber 2, as well as to allow the sample rod 1 to move up and down within the sealed space. For example, during the process of sample rod 1 moving from the top to the bottom of the transition chamber, it is only necessary to adjust the knurled nut 12 to a loose state, manually move sample rod 1 down to a fixed position, and then tighten it. During this process, the cover flange 13 does not need to be opened. Before testing the sample, the magnetic field angle dependence of the critical current Ic of the high-temperature superconducting tape can be achieved by rotating the sample rotating rod 14 to a specific angle. The conductive pins 15 of the sample rod are respectively attached with hard superconducting tape for conduction. The conductive post of the current lead 4 is also attached with hard superconducting tape for conduction. When the sample rod 1 rotates axially, the conductive pins 15 of the sample rod will make close contact with the groove of the conductive post 4 to achieve conduction. The staggered design of the conductive pins 15 of the sample rod can achieve close contact with the conductive post of the current lead 4 no matter which direction the sample rod rotates after entering the test system. After the sample slot cooling column 16 is inserted into the cooling column groove of the copper base 5, it ensures the vertical fixation of the sample rod. The two are insulated from each other to achieve sample cooling and avoid conduction. A Hall sensor and a thermometer can be attached to the sample slot cooling column 16 to monitor the temperature and magnetic field changes during the test.

[0057] Figure 3 This diagram illustrates the testing and sample changing processes in the transition chamber 2. Its purpose is to isolate the inside and outside of the testing system, ensuring that the inside of the testing system remains in a vacuum and low-temperature state. Figure 1The main structure of the intermediate transition chamber 2 is composed of manually openable and closed ball valves. In actual application, the switching of the transition chamber is not limited to a certain type of valve. It can be a ball valve, a baffle valve, or other vacuum valves 21 that can be flexibly opened and closed.

[0058] The refrigerator 3 adopts a two-stage cooling architecture with a cold head, which can achieve gradient cooling and precise temperature control. Its cooling path and assembly structure design are as follows: The first-stage cold head is directly and rigidly connected to the upper plate of the cold screen 7. Through efficient heat conduction of the metal solid-solid contact, the cold energy is transferred to the cold screen, thereby achieving overall cooling of the cold screen and isolating the interference of external heat radiation on the core low-temperature area. The second-stage cold head is flexibly connected to the copper base 5 through a copper braided flexible connector. Utilizing the excellent thermal conductivity and deformation compensation capability of the copper braid, while adapting to the assembly tolerance of the device, the cold energy is efficiently transferred to the copper base, thereby achieving uniform and stable low-temperature cooling of the sample to be tested fixed on the copper base 5.

[0059] The copper base 5 is designed with support, positioning, and insulation functions: its bottom is a disc-shaped structure, which is fastened to the upper plate of the cold shield 7 by high-strength screws to ensure the mechanical stability of the assembly; the center of the disc-shaped structure has an integrally machined cylindrical boss with a groove. This boss is not only used to precisely limit the radial position of the sample rod 1, but its surface is also covered with an aluminum nitride sheet as an insulating layer, which can effectively block the unexpected electrical conduction between the sample rod 1 and the copper base 5, avoiding interference with the electrical transport test. During the installation of the sample rod 1, when the sample rod 1 extends axially downward into the device, its bottom cylindrical section, which is made of G10 insulating material, will precisely embed into the grooved cylinder of the copper base 5. At this time, the cylindrical section and the inner wall of the groove form a rigid limiting fit, which restricts the axial displacement of the sample rod 1 and prevents it from moving further downward, thus ensuring that the sample is in the preset test position.

[0060] The loop formed by current lead 4 is as follows Figure 4 As shown, the hard superconducting strips on both sides of the sample are attached to the conductive posts of the current lead 4 and the conductive pins 15 of the sample rod 1, respectively. The experimental power supply is deployed outside the Dewar 6, with its positive and negative terminals connected to the positive and negative copper electrodes (conductive posts) of the current lead, respectively. After energization, the current flows through the copper electrodes into the hard superconducting strips pre-wound onto the electrode surface. The bottom of the conductive post of the current lead 4 is designed with a special groove structure, and the inner wall of the groove is pre-attached with hard superconducting strips. During the experiment, by rotating the sample rod 1, the conductive pins 15 (with hard superconducting strips attached to their surface) fixed at the rod end can be precisely inserted into the groove. Low-impedance contact conductivity is achieved by the tight fit between the conductive post of the current lead 4 and the hard superconducting strips of the conductive pins 15. The current flows through the hard superconducting strip into the sample to be tested, which is fixed in the sample groove cooling post 16. After the electrical transport performance test of the sample is completed, the current flows back along the original path through the hard superconducting strip and the copper electrode, and finally returns to the negative terminal of the power supply, forming a complete closed current loop.

Claims

1. A method for testing the performance of high-temperature superconducting tapes that enables rapid sample changing, characterized in that, Includes the following steps: S1, place the first sample rod containing the sample to be tested above the transition chamber, and evacuate the space inside the Dewar and above the transition chamber. S2, insert the sample rod into the cold screen, so that the sample groove cold guide column is tightly connected to the copper base, and the conductive pin of the sample rod is in close contact with the current lead; S3, start the refrigeration unit to cool the entire internal part of the device, and keep the temperature at the operating temperature after it is reduced to the operating temperature. S4. Perform voltage and current tests, temperature tests, magnetic field strength tests, and magnetic field angle tests on the sample to be tested. After the performance tests are completed, lift the sample rod to the top of the transition chamber, close the valve, and take it out. S5, place the next sample rod above the transition chamber, evacuate the space above the transition chamber, insert the sample rod into the cold screen, make the sample groove cold conduction column tightly connected to the copper base, and make the conductive pin of the sample rod in close contact with the current lead to complete the rapid sample change. S6, perform performance testing on the sample to be tested. After completion, lift the sample rod to the top of the transition chamber, close the valve, and remove it. S7, repeat S5-S6 to complete rapid sample switching and performance testing for multiple samples.

2. The method for testing the performance of high-temperature superconducting tapes with rapid sample changing as described in claim 1, characterized in that, The specific steps of S1 are as follows: S101, close the vacuum valve of the transition chamber, insert the sample rod containing the sample to be tested into the space above the transition chamber, seal the cover flange of the sample rod and the flange of the transition chamber, and tighten the knurled nut to form a sealed space above the transition chamber. S102, open the inflation valve and exhaust valve below the transition chamber to evacuate the inside of the Dewar, and at the same time open the inflation valve and exhaust valve above the transition chamber to evacuate the space above the transition chamber.

3. The method for testing the performance of high-temperature superconducting tapes with rapid sample changing as described in claim 1, characterized in that, The specific steps of S2 are as follows: S201, open the vacuum valve of the transition chamber, loosen the knurled nut of the sample rod, insert the sample rod into the cold screen and insert the sample groove cooling column into the groove of the copper base until it can no longer move downwards; S202, rotate the sample rod until it can no longer be rotated, so that the conductive pin of the sample rod is in close contact with the groove structure of the current lead, and finally tighten the knurled nut to fix the sample rod.

4. The method for testing the performance of high-temperature superconducting tapes with rapid sample changing as described in claim 1, characterized in that, In S3, the refrigerator uses a two-stage cooling system with a cold shield to conduct cold energy and isolate external heat radiation. The second-stage cold head uses a copper base to conduct cold energy, thereby achieving uniform cooling of the high-temperature superconducting tape sample to be tested.

5. A high-temperature superconducting tape performance testing device capable of rapid sample changing, characterized in that, A method for testing the performance of high-temperature superconducting tapes with rapid sample changing is provided, comprising a sample rod, a transition chamber, a cryostat, current leads, a copper base, a Dewar flask, a cold shield, and a high-temperature superconducting coil. The Dewar flask serves as the main testing chamber, creating a low-temperature vacuum testing environment. The transition chamber is connected to the Dewar flask. The cold shield, copper base, and current leads are all located inside the Dewar flask. The current leads pass through the upper plate of the cold shield and connect to the upper plate of the Dewar flask. The copper base is connected to the upper plate of the cold shield. The cryostat is connected to the cold shield and copper base to achieve staged cooling. The high-temperature superconducting coil is positioned outside the cold shield. The sample rod, containing the high-temperature superconducting tape sample to be tested, extends through the transition chamber into the Dewar flask, and engages with the copper base for positioning and with the current leads for conductivity, thus completing the performance test.

6. The high-temperature superconducting tape performance testing device with rapid sample changing capability according to claim 5, characterized in that, The sample rod has a hollow structure with an aviation plug at the top. From top to bottom, the rod body is provided with a knurled nut, a cover flange, and a sample rotating rod. The lower end of the rod body is provided with a sample rod conductive pin and a sample groove cooling column. The aviation plug is connected to a voltage lead, which passes through the hollow interior of the sample rod and is connected to both ends of the sample rotating rod.

7. The high-temperature superconducting tape performance testing device capable of rapid sample changing according to claim 5, characterized in that, Hard superconducting strips are attached to the conductive pins of the sample rod and the conductive posts of the current leads, and the conductive pins of the sample rod are designed to be misaligned.

8. The high-temperature superconducting tape performance testing device capable of rapid sample changing according to claim 6, characterized in that, The sample tank cooling column is equipped with a Hall sensor and a thermometer.

9. The high-temperature superconducting tape performance testing device capable of rapid sample changing according to claim 5, characterized in that, The refrigeration unit is a two-stage refrigeration structure with a primary cold head connected to the upper plate of the cold shield, and a secondary cold head connected to the copper base.

10. The high-temperature superconducting tape performance testing device capable of rapid sample changing according to claim 5, characterized in that, The copper base includes a bottom disc-shaped structure, the center of which has a grooved cylindrical boss, and the surface of the cylindrical boss is provided with an insulating layer.

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