CN116027112B - A kind of testing device and testing method for superconducting joint without back field - Google Patents

Abstract

The invention relates to the field of superconducting magnet tests and discloses a device and a method for testing a superconducting joint without a back field. The beneficial effects of the invention are as follows: the superconducting joint is arranged on a fixed tool, parameters such as resistance, voltage drop and the like of one or more superconducting joints can be tested simultaneously, different types of superconducting joints can be tested, the resistance under the current of dozens of KA levels can be tested, the resistance as low as 0.1nΩ can be tested, the voltage drop test under 4.2K and the voltage drop test under normal temperature can be performed, the test efficiency is high, the test data error is small, and the precision is high.

Description

A kind of testing device and testing method for superconducting joint without back field

technical field

The invention relates to the field of superconducting magnet testing, in particular to a superconducting joint non-back field testing device and a testing method thereof.

Background technique

In the winding process of superconducting magnet coils, since the length of the superconducting wire cannot be infinitely long, or it can be customized segment by segment due to actual engineering requirements, these require the connection to solve the length problem. Therefore, the connection technology of the superconducting wire has become A key technology in practical application. At present, the types of superconducting joints include box joints, sintered joints, butt joints, coaxial lap joints, etc. During the development of these joints, their performance needs to be tested and evaluated, for example, joints under no back field Resistors, etc., especially for sintered joints, which have no back field resistance requirements as low as 0.1 nΩ at 4.2 K. Therefore, it is particularly important to develop a testing device and a testing method for a superconducting joint without a backing field. However, there is no device and a corresponding testing method for testing a superconducting joint in an environment without a backing field in the prior art.

Contents of the invention

The purpose of this application is to provide a superconducting joint non-back field testing device and its testing method, which can efficiently test superconducting joints, quickly and accurately obtain the resistance of superconducting joints, and can complete the Pressure drop test under conditions.

The purpose of this application is achieved through the following technical solutions:

A test device for a superconducting joint without a back field, comprising:

A power supply, a terminal box, a test component, a first cooling unit, a first recovery unit, a second cooling unit, and a second recovery unit, the terminal box has an accommodating space, and the test component is arranged in the accommodating space;

The test assembly includes a first current lead, a fixing tool, a connection part and a second current lead, the positive pole of the power supply is electrically connected to the first end of the first current lead, and the second end of the first current lead A first installation position for installing a superconducting joint is defined together with the fixing tool, and a second installation position for installing a superconducting joint is formed by the fixing tool and the first end of the second current lead. position, the first installation position and the second installation position are connected through the connection part, and the connection part is provided on the side of the first installation position away from the first current lead, the The second end of the second current lead is electrically connected to the negative pole of the power supply;

The first cooling part communicates with the first end of the first current lead, the first recovery part communicates with the second end of the first current lead, and the first cooling part communicates with the second current lead. The second end of the lead is connected, and the first recovery part is connected with the first end of the second current lead;

The second cooling part communicates with the second end of the first current lead, and the second recovery part communicates with the first end of the second current lead;

The first cooling part is cooled by liquid nitrogen, and the second cooling part is cooled by liquid helium;

The first end of the first current lead is a feed end and a helium tube, there are two helium tubes in the middle of the first current lead, and one of the helium tubes communicates with the second end of the first current lead, Another helium tube communicates with the helium tube at the first end of the first current lead; the second end of the second current lead is a feeder end and a helium tube, and there are two helium tubes in the middle of the second current lead One of the helium tubes communicates with the first end of the second current lead, the other helium tube communicates with the helium tube at the second end of the second current lead, and the two feed ends are respectively connected to the positive side of the power supply. negative electrode.

In some embodiments of the present application, an air extraction system is also included, and the air extraction system communicates with the accommodating space.

In some embodiments of the present application, a leak detection system is also included, and the leak detection system communicates with the accommodating space.

In some embodiments of the present application, a cold shield is also included, the cold shield is attached to the inner side of the terminal box, the inlet end of the cold shield communicates with the first cooling part, and the outlet of the cold shield The end communicates with the first recovery part.

In some embodiments of the present application, it further includes a first connecting pipe and a second connecting pipe, the first connecting pipe communicates with the first end of the first current lead and the second end of the second current lead, and The first connection pipe communicates with the first cooling part, the second connection pipe communicates with the second end of the first current lead and the first end of the second current lead, and the second connection The pipe communicates with the first recovery part.

A method for testing a superconducting joint without a backing field, using the above-mentioned superconducting joint without a backing field testing device, comprising the following steps:

Installing the first superconducting joint on the first installation position, installing the second superconducting joint on the second installation position, so that the first superconducting joint is respectively connected to the first current lead and the communicating with the connecting portion, so that the second superconducting joint communicates with the connecting portion and the second current lead respectively;

installing pressure transmitters at both ends of the first superconducting joint and at both ends of the second superconducting joint;

installing thermometers at both ends and the middle position of the first superconducting joint, and at both ends and the middle position of the second superconducting joint;

Install a first potential line at the connection position between the first current lead and the first superconducting joint, install a second potential line at both ends of the first superconducting joint, and install A third potential line is installed at both ends, and a fourth potential line is installed at the connection position between the second superconducting joint and the second current lead;

Turn on the first cooling unit and the first recovery unit, then turn on the second cooling unit and the second recovery unit, turn on the power supply and gradually increase the delivery current, record the pressure transmitter, the According to the data of the thermometer and the potential line, the resistance of the superconducting joint is calculated by using the linear fitting current-voltage curve;

Stabilize the superconducting joint in the superconducting state, then control the cooling flow rate of the second cooling part to gradually decrease, record the data of the pressure transmitter, and record the side of the first superconducting joint close to the connecting part record the thermometer data on the side of the second superconducting joint close to the connecting portion;

Stabilize the superconducting joint at room temperature, then control the cooling flow rate of the second cooling part to gradually decrease, record the data of the pressure transmitter, and record the temperature of the first superconducting joint near the connecting part. Thermometer data, recording the thermometer data on the side of the second superconducting joint close to the connection part.

In some embodiments of the present application, the first superconducting joint, the first current lead, the second superconducting joint and the second current lead all have a single joint box, and the first superconducting joint The single junction box of the first current lead and the single junction box of the first current lead are connected by an indium crimping process to form a first double junction box, the single junction box of the second superconducting junction and the single junction box of the second current lead The second double junction box is formed by indium crimping process, the first potential line is connected to both ends of the first double junction box, and the fourth potential line is connected to both ends of the second double junction box .

In some embodiments of the present application, an insulator is also included, the insulator is provided between the pressure transmitter and the first superconducting joint, and the insulator is provided between the pressure transmitter and the second superconducting joint. The insulator is provided.

The superconducting joint non-back field testing device and testing method thereof of the present application install the superconducting joint on a fixed tooling, can simultaneously test parameters such as resistance and voltage drop of one or more superconducting joints, and can test different types of superconducting joints Superconducting joints can test the resistance of dozens of KA-level currents, and can test the resistance as low as 0.1nΩ. It can perform the voltage drop test at 4.2K and the voltage drop test at room temperature. It has high test efficiency and small test data error. High precision.

Description of drawings

Fig. 1 is the structure diagram of the superconducting joint without back field testing device of the present application;

Fig. 2 is the schematic diagram of the installation position of pressure transmitter and thermometer of the present application;

Fig. 3 is a schematic diagram of the installation position of the potential line of the present application.

In the figure, 1. power supply; 2. terminal box; 3. test component; 31. first current lead; 32. fixed tooling; 33. connecting part; 34. second current lead; 35. first superconducting joint; 36 . The second superconducting joint; 4. The first cooling part; 5. The first recovery part; 6. The second cooling part; 7. The second recovery part; The second installation position; 11. Air extraction system; 12. Leak detection system; 13. Cold screen; 14. First connecting pipe; 15. Second connecting pipe; 16. Pressure transmitter; 17. Thermometer; 18. The second A potential line; 19, a second potential line; 20, a third potential line; 21, a fourth potential line; 22, an insulator.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

In the description of the present application, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. used in the present application indicate orientation or positional relationship based on the drawings The orientations or positional relationships shown are only for the convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as an important aspect of the present invention. limits. In addition, the terms "first", "second", etc. are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

As shown in Figure 1, the embodiment of the present application proposes a superconducting joint without back field testing device, including:

Power supply 1, terminal box 2, test assembly 3, first cooling unit 4, first recovery unit 5, second cooling unit 6, and second recovery unit 7, the terminal box 2 has an accommodating space 8, and the test assembly 3 is set in the accommodating space 8;

The test assembly 3 includes a first current lead 31, a fixing tool 32, a connecting portion 33 and a second current lead 34, the positive pole of the power supply 1 is electrically connected to the first end of the first current lead 31, and the first A second end of a current lead 31 is jointly defined with the fixing tool 32 to form a first installation position 9 for installing a superconducting joint, and the fixing tool 32 is jointly defined with the first end of the second current lead 34 A second installation position 10 for installing superconducting joints is formed, the first installation position 9 and the second installation position 10 are connected through the connection part 33, and the connection part 33 is arranged on the The first installation position 9 is away from the side of the first current lead 31, and the second end of the second current lead 34 is electrically connected to the negative pole of the power supply 1;

The first cooling part 4 communicates with the first end of the first current lead 31, the first recovery part 5 communicates with the second end of the first current lead 31, and the first cooling part 4 communicates with the first end of the first current lead 31. The second end of the second current lead 34 is communicated, and the first recovery part 5 is communicated with the first end of the second current lead 34;

The second cooling part 6 communicates with the second end of the first current lead 31 , and the second recovery part 7 communicates with the first end of the second current lead 34 ;

The first cooling part 4 is cooled by liquid nitrogen, and the second cooling part 6 is cooled by liquid helium;

The first end of the first current lead 31 is a feed end and a helium tube, and there are two helium tubes in the middle of the first current lead 31, one of which is connected to the second end of the first current lead 31. The other helium tube communicates with the helium tube at the first end of the first current lead 31; the second end of the second current lead 34 is a feeder terminal and a helium tube, and the second current lead 34 There are two helium tubes in the middle, one of which communicates with the first end of the second current lead 34, the other communicates with the helium tube of the second end of the second current lead 34, and the two feed Terminals are respectively connected to the positive and negative poles of the power supply 1.

Based on the above-mentioned technical scheme, in the superconducting joint non-back field testing device of the present application, the power supply 1 provides test current for the entire testing device, and the current of the power supply 1 passes through the first current lead 31, the superconducting joint at the first installation position 9, and The connecting part 33, the superconducting joint of the second installation position 10 and the second current lead 34 return to the negative pole, wherein the superconducting joint is preferably made of a CICC superconducting conductor, and the connecting part 33 preferably adopts a U-shaped bend structure. The first end of the current lead 31 is a feeder end and a helium tube, and there are two helium tubes in the middle of the first current lead 31, wherein one helium tube communicates with the second end of the first current lead 31, and the other helium tube communicates with the second end of the first current lead 31. The helium tube at the first end of the first current lead 31 communicates; the second end of the second current lead 34 is a feeder end and a helium tube, and there are two helium tubes in the middle of the second current lead 34, one of which is connected to the second helium tube. The first end of the second current lead 34 is connected, and the other helium tube is connected with the helium tube at the second end of the second current lead 34, and the two feed ends are respectively connected to the positive and negative poles of the power supply 1, and the helium tube can play the role of introducing refrigerant. role, such as liquid helium, liquid nitrogen, etc.

The first cooling unit 4 is preferably an 80K liquid nitrogen supply system, the first recovery unit 5 is preferably an 80K liquid nitrogen recovery system, the second cooling unit 6 is preferably a 4.2K liquid nitrogen supply system, and the second recovery unit 7 is preferably a 300K helium gas Recovery system, the first cooling part 4 supplies liquid nitrogen with a temperature of 80K, 80K liquid nitrogen enters the first current lead 31 through the helium tube at the first end of the first current lead 31, and passes through a helium in the middle of the first current lead 31 The tube flows out to the first recovery part 5, thereby constituting the cooling channel of the first current lead 31; 80K liquid nitrogen enters the second current lead 34 through the helium tube at the second end of the second current lead 34, and passes through the second A helium tube in the middle flows out to the first recovery part 5 , thereby forming a cooling channel for the second current lead 34 , and the above structure cooperates to complete the cooling of the two current leads. The second cooling part 6 supplies liquid helium with a temperature of 4.2K, and the 4.2K liquid helium enters the first current lead 31 through another helium tube in the middle of the first current lead 31, and passes through the first current lead 31, the first superconducting joint 35 , the connection part 33 , the second superconducting joint 36 and the second current lead 34 , and finally flows out to the second recovery part 7 through another helium tube in the middle of the second current lead 34 , thereby forming the cooling channel of the test assembly 3 . The reason why the current lead and the test component 3 adopt different cooling methods is that the current lead only needs to be cooled by liquid nitrogen at a temperature of 80K, while the test component 3 needs to reach a superconducting state to meet the test requirements. However, the test component 3 needs a temperature lower than 80K to reach the superconducting state. At this time, liquid nitrogen cannot meet the ultra-low temperature condition, so liquid helium with better cooling effect needs to be used to reach 4.2K that meets the superconducting condition. temperature, and because the cost of liquid helium is much higher than that of liquid nitrogen, it is only necessary to use liquid helium at a suitable position, and it is not necessary to use liquid helium for cooling the entire device, so this method of using liquid nitrogen and liquid helium together is used. test.

In some embodiments of the present application, as shown in FIG. 1 , an air extraction system 11 is further included, and the air extraction system 11 communicates with the accommodating space 8 . The air pumping system 11 can vacuum the accommodating space 8 in the terminal box 2, so as to meet the superconducting requirements of the superconducting joint.

Specifically, as shown in FIG. 1 , a leak detection system 12 is also included, and the leak detection system 12 communicates with the accommodating space 8 . The leak detection system 12 can detect whether there are tiny gaps in the accommodating space 8 of the terminal box 2, so as to prevent inaccurate test data caused by cold air leakage.

In some embodiments of the present application, as shown in FIG. 1 , a cold shield 13 is also included, and the cold shield 13 is attached to the inner side of the terminal box 2. The inlet end of the cold shield 13 is connected to the first The cooling part 4 communicates, and the outlet end of the cold screen 13 communicates with the first recovery part 5 . The cold shield 13 is a shielding structure arranged inside the terminal box 2, which can introduce cooling substances in the first cooling part 4, such as liquid nitrogen, to create a low-temperature environment for the terminal box 2 and maintain the low temperature of the test assembly 3.

In some embodiments of the present application, as shown in FIG. 1 , the first cooling part 4 is cooled by liquid nitrogen. The cooling effect of liquid nitrogen is good, the cost is low, and it can simply and effectively meet the requirements of creating a low temperature environment.

Specifically, as shown in FIG. 1 , the second cooling part 6 is cooled by liquid helium. The cost of liquid helium is relatively high, but it can produce a low temperature as low as 4.2K, which can perfectly simulate the low-temperature superconducting environment of the superconducting joint and meet the requirements of the test.

In some embodiments of the present application, as shown in FIG. 1 , a first connecting pipe 14 and a second connecting pipe 15 are also included, and the first connecting pipe 14 communicates with the first end of the first current lead 31 and the The second end of the second current lead 34, and the first connection pipe 14 communicates with the first cooling part 4, and the second connection pipe 15 communicates with the second end of the first current lead 31 and the The first end of the second current lead 34 , and the second connecting pipe 15 communicates with the first recovery part 5 . The first connecting pipe 14 and the second connecting pipe 15 are used for drainage, so that the first current lead 31 and the second current lead 34 communicate with the first cooling part 4 and the first recovery part 5 , without separate connection. The first connecting pipe 14 and the second connecting pipe 15 are preferably made of stainless steel, which not only can adapt to the ambient temperature, but also are easy to obtain and low in cost.

As shown in Figures 1-3, the embodiment of the present application proposes a method for testing a superconducting joint without a backing field, using the above-mentioned testing device for a superconducting joint without a backing field, including the following steps:

The first superconducting joint 35 is installed on the first installation position 9, and the second superconducting joint 36 is installed on the second installation position 10, so that the first superconducting joint 35 is respectively connected to the first installation position 9. A current lead 31 communicates with the connection part 33, so that the second superconducting joint 36 communicates with the connection part 33 and the second current lead 34 respectively;

Install pressure transmitters 16 at both ends of the first superconducting joint 35 and at both ends of the second superconducting joint 36;

Install thermometers 17 at both ends and the middle position of the first superconducting joint 35, and at both ends and the middle position of the second superconducting joint 36;

Install the first potential line 18 at the connecting position of the first current lead 31 and the first superconducting joint 35, install the second potential line 19 at the two ends of the first superconducting joint 35, and install the second potential line 19 at the two ends of the first superconducting joint 35. A third potential line 20 is installed at both ends of the two superconducting joints 36, and a fourth potential line 21 is installed at the connection position between the second superconducting joint 36 and the second current lead 34;

Open the first cooling unit 4 and the first recovery unit 5, then open the second cooling unit 6 and the second recovery unit 7, turn on the power supply 1 and gradually increase the delivery current, record the pressure transmitter 16, the thermometer 17 and The data of the potential line, using the linear fitting current-voltage curve to calculate the resistance of the superconducting joint;

Stabilize the superconducting joint in the superconducting state, then control the cooling flow rate of the second cooling part 6 to gradually decrease, record the data of the pressure transmitter 16, and record that the first superconducting joint 35 is close to the connection The data of the thermometer 17 on the side of the part 33, recording the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting part 33;

Stabilize the superconducting joint at room temperature, then control the cooling flow rate of the second cooling part 6 to gradually decrease, record the data of the pressure transmitter 16, and record that the first superconducting joint 35 is close to the connecting part 33, record the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting portion 33.

In some embodiments of the present application, as shown in Figures 1-3, the first superconducting joint 35, the first current lead 31, the second superconducting joint 36 and the second current lead 34 are There is a single joint box, the single joint box of the first superconducting joint 35 and the single joint box of the first current lead 31 are connected by an indium crimping process to form a first double joint box, and the second superconducting joint 36 The single junction box of the single junction box and the single junction box of the second current lead 34 are connected by indium crimping process to form a second double junction box, and the first potential line 18 is connected to both ends of the first double junction box, so The fourth potential line 21 is connected to both ends of the second double junction box. In some embodiments, the test sample is integrally formed, including the first superconducting joint 35, the second superconducting joint 36 and the connecting part 33, the single joint box on the first superconducting joint 35 and the first superconducting joint 35 is integrally formed, and the single joint box on the second superconducting joint 36 is integrally formed with the second superconducting joint 36 . Like this, when the test sample needs to be replaced, only the test sample needs to be disassembled from the fixed tooling 32, and the two single joint boxes on the two superconducting joints are disassembled from the two current leads, and then replaced with new ones. For the test sample, just crimp the two single-junction boxes on the new test sample to the two current leads.

In some embodiments of the present application, as shown in FIG. 2 , an insulator 22 is also included. The insulator 22 is provided between the pressure transmitter 16 and the first superconducting joint 35. The pressure transmitter The insulator 22 is provided between the 16 and the second superconducting joint 36 . The insulator 22 can prevent the high current of the test device from affecting the pressure test accuracy of the pressure transmitter 16. The insulator 22 is preferably an axial insulator 22, which can effectively shield the axial current of the wire.

The detailed process of the whole test method is explained here:

Open the side hatch of the terminal box 2, install the current leads on the terminal box 2, install the test component 3 inside the terminal box 2, and use the indium crimping process to respectively connect a pair of single junction boxes of the test component 3 and a pair of current leads. A single junction box, forming a pair of feeding double junction boxes. The two single junction boxes feeding the double junction box are connected by stainless steel pipes.

Pressure transmitters 16 are respectively installed at both ends of the first superconducting joint 35 of the test assembly 3 , and pressure transmitters 16 are respectively installed at both ends of the second superconducting joint 36 of the test assembly 3 .

A thermometer 17 is installed at both ends of the first superconducting joint 35 of the test assembly 3 , and a thermometer 17 is installed in the middle of the first superconducting joint 35 .

A thermometer 17 is installed at both ends of the second superconducting joint 36 of the test assembly 3 , and a thermometer 17 is installed in the middle of the second superconducting joint 36 .

A pair of first potential wires 18 is installed at both ends of the feeding double junction box between the first superconducting joint 35 and the first current lead 31 . Two pairs of second potential lines 19 are installed at both ends of the first superconducting joint 35, wherein one pair of second potential lines 19 is a spare line.

Two pairs of third potential wires 20 are installed at both ends of the second superconducting joint 36, wherein one pair of third potential wires 20 is a spare wire. A pair of fourth potential wires 21 are installed at both ends of the feeding double junction box between the second superconducting joint 36 and the second current lead 34 .

Seal the terminal box 2, open the air extraction system 11 and the leak detection system 12 of the terminal box 2, and carry out vacuum pumping and leak detection on the terminal box 2. Turn on the temperature acquisition system, pressure acquisition system and potential acquisition system, and debug these systems. After the commissioning is completed, when the vacuum degree of the terminal box 2 reaches below 1Pa, turn on the 80 K liquid nitrogen supply system and the 80 K liquid nitrogen recovery system, and when the temperature of the terminal box 2 and the current lead drops to about 80 K, turn on the 4.2 K liquid nitrogen Helium supply system and 300 K helium recovery system.

Connect the two current lead feed ends to the positive and negative poles of the power supply 1 respectively.

When the temperature of the test component 3 is stable at 4.2-6 K, turn on the power supply 1, inject current into the system, and slowly increase the current to 0 kA, 10 kA, 20 kA, 30 kA, 40 kA, 50 kA and above, each current Stable for at least 2 min. Record the data of all thermometers 17, potential wires, and pressure transmitters 16. The resistance of the junction was calculated using a linear fit to the I-V curve.

After completing the above resistance test, when the temperature of the superconducting joint is stable at 4.6-6 K:

Control the flow rate of helium to 5±0.2g/s, and keep it stable for 2 minutes, record the data of the pressure transmitter 16 at this time, and the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting part 33;

Control the flow of helium to 4.5±0.2g/s, and keep it stable for 2 minutes, record the data of the pressure transmitter 16 at this time, and the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting part 33;

Control the flow of helium to 4±0.2g/s, and keep it stable for 2 minutes, record the data of the pressure transmitter 16 at this time, and the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting part 33;

Control the flow of helium to 3.5±0.2g/s, and keep it stable for 2 minutes, record the data of the pressure transmitter 16 at this time, and the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting part 33;

Control the flow rate of helium to 3±0.2g/s, and keep it stable for 2 minutes, record the data of the pressure transmitter 16 at this time, and the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting part 33 .

After the 4.2 K pressure drop test of test component 3 was completed, the temperature of test component 3 was raised. During the whole temperature rise process, the temperature gradient of the inlet and outlet pipelines of the superconducting joint of test component 3 was kept <50 K.

Warm up the entire system to room temperature, and when the temperature of the superconducting junction stabilizes at room temperature:

Control the flow rate of helium to 5±0.2g/s, and keep it stable for 2 minutes, record the data of the pressure transmitter 16 at this time, and the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting part 33 .

Control the flow rate of helium to 4.5±0.2g/s, and keep it stable for 2 minutes, record the data of the pressure transmitter 16 at this time, and the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting part 33 .

Control the flow rate of helium to 4±0.2g/s, and keep it stable for 2 minutes, record the data of the pressure transmitter 16 at this time, and the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting part 33 .

Control the flow rate of helium to 3.5±0.2g/s, and keep it stable for 2 minutes, record the data of the pressure transmitter 16 at this time, and the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting part 33 .

Control the flow rate of helium to 3±0.2g/s, and keep it stable for 2 minutes, record the data of the pressure transmitter 16 at this time, and the data of the thermometer 17 on the side of the second superconducting joint 36 close to the connecting part 33 .

After completing the above voltage drop test at room temperature, open the terminal box 2 hatch and remove the test component 3 from the current leads.

In summary, the superconducting joint non-back field testing device and its testing method of the present application install the superconducting joint on the fixed tooling 32, and can simultaneously test parameters such as resistance and voltage drop of one or more superconducting joints, and can It can test different types of superconducting joints, can test the resistance under dozens of KA level current, can test the resistance as low as 0.1nΩ, can perform the voltage drop test at 4.2K and the voltage drop test at normal temperature, the test efficiency is high, and the test The data error is small and the precision is high.

The above are only the preferred embodiments of the present application. It should be pointed out that for those of ordinary skill in the art, some improvements and substitutions can be made without departing from the technical principles of the present application. These improvements and substitutions should also be It is regarded as the scope of protection of this application.

Claims (8)

1. A superconducting joint without a back field testing device, characterized in that it comprises: A power supply, a terminal box, a test component, a first cooling unit, a first recovery unit, a second cooling unit, and a second recovery unit, the terminal box has an accommodating space, and the test component is arranged in the accommodating space; The test assembly includes a first current lead, a fixing tool, a connection part and a second current lead, the positive pole of the power supply is electrically connected to the first end of the first current lead, and the second end of the first current lead A first installation position for installing a superconducting joint is defined together with the fixing tool, and a second installation position for installing a superconducting joint is formed by the fixing tool and the first end of the second current lead. position, the first installation position and the second installation position are connected through the connection part, and the connection part is provided on the side of the first installation position away from the first current lead, the The second end of the second current lead is electrically connected to the negative pole of the power supply; The first cooling part communicates with the first end of the first current lead, the first recovery part communicates with the second end of the first current lead, and the first cooling part communicates with the second current lead. The second end of the lead is connected, and the first recovery part is connected with the first end of the second current lead; The second cooling part communicates with the second end of the first current lead, and the second recovery part communicates with the first end of the second current lead; The first cooling part is cooled by liquid nitrogen, and the second cooling part is cooled by liquid helium; The first end of the first current lead is a feed end and a helium tube, there are two helium tubes in the middle of the first current lead, and one of the helium tubes communicates with the second end of the first current lead, Another helium tube communicates with the helium tube at the first end of the first current lead; the second end of the second current lead is a feeder end and a helium tube, and there are two helium tubes in the middle of the second current lead One of the helium tubes communicates with the first end of the second current lead, the other helium tube communicates with the helium tube at the second end of the second current lead, and the two feed ends are respectively connected to the positive side of the power supply. negative electrode. 2 . The backfield-free testing device for superconducting joints according to claim 1 , further comprising an air extraction system, the air extraction system being in communication with the accommodating space. 3 . 3 . The superconducting joint back-field-free testing device according to claim 2 , further comprising a leak detection system, and the leak detection system communicates with the accommodating space. 4 . 4. The superconducting joint non-back field testing device according to claim 1, further comprising a cold screen, the cold screen is attached to the inner side of the terminal box, and the inlet end of the cold screen is connected to the The first cooling part communicates, and the outlet end of the cold shield communicates with the first recovery part. 5. The device for testing a superconducting joint without a back field according to claim 1, further comprising a first connecting pipe and a second connecting pipe, the first connecting pipe communicates with the first connecting pipe of the first current lead. end and the second end of the second current lead, and the first connecting pipe communicates with the first cooling part, and the second connecting pipe communicates with the second end of the first current lead and the first The first ends of the two current leads, and the second connecting pipe communicates with the first recovery part. 6. A method for testing a superconducting joint without a back field, characterized in that the application of the test device for a superconducting joint without a back field as claimed in any one of claims 1-5 comprises the following steps: Installing the first superconducting joint on the first installation position, installing the second superconducting joint on the second installation position, so that the first superconducting joint is respectively connected to the first current lead and the communicating with the connecting portion, so that the second superconducting joint communicates with the connecting portion and the second current lead respectively; installing pressure transmitters at both ends of the first superconducting joint and at both ends of the second superconducting joint; installing thermometers at both ends and the middle position of the first superconducting joint, and at both ends and the middle position of the second superconducting joint; Install a first potential line at the connection position between the first current lead and the first superconducting joint, install a second potential line at both ends of the first superconducting joint, and install A third potential line is installed at both ends, and a fourth potential line is installed at the connection position between the second superconducting joint and the second current lead; Turn on the first cooling unit and the first recovery unit, then turn on the second cooling unit and the second recovery unit, turn on the power supply and gradually increase the delivery current, record the pressure transmitter, the According to the data of the thermometer and the potential line, the resistance of the superconducting joint is calculated by using the linear fitting current-voltage curve; Stabilize the superconducting joint in the superconducting state, then control the cooling flow rate of the second cooling part to gradually decrease, record the data of the pressure transmitter, and record the side of the first superconducting joint close to the connecting part record the thermometer data on the side of the second superconducting joint close to the connecting portion; Stabilize the superconducting joint at room temperature, then control the cooling flow rate of the second cooling part to gradually decrease, record the data of the pressure transmitter, and record the temperature of the first superconducting joint near the connecting part. Thermometer data, recording the thermometer data on the side of the second superconducting joint close to the connection part. 7. The method for testing a superconducting joint without a back field according to claim 6, wherein the first superconducting joint, the first current lead, the second superconducting joint and the second current Each lead wire has a single joint box, the single joint box of the first superconducting joint and the single joint box of the first current lead are connected by an indium crimping process to form a first double joint box, and the single joint box of the second superconducting joint The single junction box and the single junction box of the second current lead are connected through an indium crimping process to form a second double junction box, the first potential line is connected to both ends of the first double junction box, and the fourth The potential wires are connected to both ends of the second double junction box. 8. The method for testing a superconducting joint without a back field according to claim 6, further comprising an insulator, the insulator is arranged between the pressure transmitter and the first superconducting joint, the The insulator is provided between the pressure transmitter and the second superconducting joint.

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