CN112614643B - Compact superconducting magnet device with room temperature magnetic field cavity - Google Patents

Abstract

The invention belongs to the technical field of superconducting magnet application, and relates to a compact superconducting magnet device with a room temperature magnetic field cavity. The superconducting magnet device of the present invention includes components such as a coil annular chamber, a superconducting coil and a casing chamber. The superconducting coil is arranged in the accommodating cavity formed by the coil annular cavity, and the coil annular cavity is arranged inside the casing cavity. The superconducting coil is cooled by cooling medium flowing in the coil annular chamber, and the vacuum layer between the coil annular chamber and the shell chamber plays a role of heat insulation. The center of the coil can provide a room temperature magnetic field. In the superconducting magnet device of the present invention, the coil annular chamber extends out of the casing, there is only one sealing feed-through between the coil annular chamber and the environment, and the sealing surface is outside the magnet, the sealing is simple, and the repairability is good.

Description

A compact superconducting magnet device with a room-temperature magnetic field cavity

technical field

The invention belongs to the technical field of superconducting magnet applications, and in particular relates to a compact superconducting magnet device with a room-temperature magnetic field cavity.

Background technique

Under the action of a magnetic field environment, the state, structure and properties of matter often undergo significant changes. Because superconducting materials have high flow capacity, they can provide higher background magnetic field strength than ordinary conductor magnets, which will be very helpful to promote the exploration and research of physics, chemistry, biology and other disciplines in high-field environments.

In the prior art, because the superconducting material has superconducting properties only below the critical temperature, the magnetic field space generated by the superconducting magnet is in a low temperature environment, which cannot provide a room temperature magnetic field environment.

In the prior art, it is necessary to lead the strong and weak electrical connections and cooling channels of the superconducting magnet to the room temperature environment, and at the same time, it is necessary to wrap the magnet with a vacuum layer to reduce heat leakage. It is necessary to achieve two sealed feedthroughs between the superconducting magnet and the vacuum layer, and between the vacuum layer and the environment, which increases the complexity of the feedthrough implementation. At the same time, when the feedthrough between the magnet and the vacuum layer fails, it is difficult to repair because it is inside the entire magnet device, and the operation reliability is poor. For example, the Chinese patent application with the publication number CN109300646A and the name "coil structure for superconducting magnets and superconducting magnets" uses heat transfer tubes to conduct heat for cooling, and the device is placed in a cryostat, which produces The central magnetic fields of all are in a low-temperature environment, and it is impossible to obtain a room-temperature magnetic field space.

SUMMARY OF THE INVENTION

The object of the present invention is to propose a compact superconducting magnet device with a room temperature magnetic field cavity, in addition to the coil structure for the superconducting magnet, it is also provided with a heat transfer tube thermally coupled with the coil to provide a room temperature magnetic field Space for other experiments that require a magnetic field at room temperature. At the same time, the magnet has only one sealing feedthrough between the superconducting magnet and the environment, and the sealing surface is outside the magnet, so the sealing is easy to realize and the repairability is good.

The present invention proposes a compact superconducting magnet device with a room-temperature magnetic field cavity, comprising a housing with a vacuum chamber and a superconducting coil; the superconducting coil is placed in the coil chamber in the housing with a vacuum chamber, A vacuum flange port is provided on the outer wall of the housing with a vacuum chamber, the vacuum chamber is sealed and connected to the vacuum pump through the vacuum flange port, and an insulating pad is provided in the vacuum chamber of the housing; the coil chamber is connected to the liquid nitrogen The pipelines are connected, and the liquid nitrogen through the liquid nitrogen pipeline flows through the coil chamber to cool the superconducting coil, so that the superconducting coil has superconducting performance; the coils of the superconducting coil are provided with inter-coil terminals, and the superconducting coil The superconducting coil is connected to the electric vacuum feedthrough through the superconducting coil terminal and the electrical connector, and the superconducting coil is energized through the electric feedthrough and the electrical connector. The superconducting coil excites a magnetic field in the energized state, and the magnetic field space is located in the center of the superconducting coil within the cavity.

In the above-mentioned superconducting magnet device, the coil chamber extends out of the casing with a vacuum chamber, wherein the coil chamber communicates with the cavity of the extension section.

In the above-mentioned superconducting magnet device, all or part of the liquid nitrogen pipeline adopts bellows to relieve the thermal stress of the superconducting magnet device during operation.

In the above-mentioned superconducting magnet device, all or part of the electrical connector is made of copper braid to relieve the thermal stress of the superconducting magnet device during operation.

The compact superconducting magnet device with a room temperature magnetic field cavity of the present invention has the following advantages:

The present invention has a compact superconducting magnet device with a room temperature magnetic field cavity. Compared with other superconducting magnet devices, the magnetic field space provided by the present invention is at room temperature. There is a sealing feedthrough between the chamber and the environment, and the sealing surface is outside the magnet, so the sealing is easy to realize and the repairability is good.

Description of drawings

Fig. 1 is a structural schematic diagram of a compact superconducting magnet device with a room temperature magnetic field cavity proposed by the present invention.

Fig. 2 is a schematic diagram of the appearance of the superconducting magnet device of the present invention.

In Fig. 1-Fig. 2, 1 is the electric vacuum feedthrough, 2 is the electrical connector, 3 is the vacuum flange port, 4 is the shell with a vacuum chamber, 5 is the coil chamber, 6 is the insulating pad, 7 8 is a terminal between coils, 9 is a superconducting coil terminal, 10 is a liquid nitrogen pipeline, 11 is an insulating gasket, 12 is an outer wall front end cover, and 13 is a partition.

Detailed ways

The present invention proposes a compact superconducting magnet device with a room temperature magnetic field cavity, its structure as shown in Figure 1 and Figure 2, including a housing 4 with a vacuum chamber and a superconducting coil 7; the superconducting coil 7 is placed In the coil chamber 5 in the shell 4 with the vacuum chamber, the outer wall of the shell 4 with the vacuum chamber is provided with a vacuum flange port 3, and the vacuum chamber is connected to the vacuum pump (not shown in the figure) through the vacuum flange port 3 out) sealed connection, the vacuum chamber of the shell 4 is provided with an insulating spacer 6; the coil chamber 5 communicates with the liquid nitrogen pipeline 10, and the liquid nitrogen passing through the liquid nitrogen pipeline 10 flows through the coil chamber 5 to cool The superconducting coil makes the superconducting coil 7 have superconducting properties; the coils of the superconducting coil 7 are provided with inter-coil terminals 8, and the superconducting coil 7 is connected to the electric vacuum through the superconducting coil terminal 9 and the electrical connector 2 The feedthroughs 1 are connected, and the superconducting coil 7 is energized through the electric feedthrough 1 and the electrical connector 2. The superconducting coil excites a magnetic field in the energized state, and the magnetic field space is located in the cavity at the center of the superconducting coil 7.

In the above superconducting magnet device, the coil chamber 5 extends out of the casing 4 with a vacuum chamber, wherein the coil chamber 5 communicates with the cavity of the extension section.

In the above-mentioned superconducting magnet device, all or part of the liquid nitrogen pipeline 10 adopts bellows to relieve the thermal stress of the superconducting magnet device during operation.

In the above superconducting magnet device, all or part of the electrical connector 2 is made of copper braid to relieve the thermal stress of the superconducting magnet device during operation.

In the compact superconducting magnet device with a room temperature magnetic field cavity of the present invention, the electrical connector 2 is used to connect the superconducting coil terminal 9 of the superconducting coil 7 , and the electrical connector 2 is guided by an insulating washer 11 . Copper braid is used to connect the electrical connector 2 with the external electrical vacuum feedthrough 1 . The electric vacuum feedthrough 1 is in sealing connection with the front end cover 12 of the outer wall of the coil chamber 5 .

In the superconducting magnet device of the present invention, part or all of the liquid nitrogen pipeline 10 is flexibly connected with bellows, and the liquid nitrogen pipeline 10 is sealed and connected with the front end cover 12 of the outer wall of the coil chamber. The shell 4 with the vacuum chamber is sealed and connected with the vacuum pump (not shown in the figure) through the vacuum flange port 3 .

A compact superconducting magnet device with a room temperature magnetic field cavity according to an embodiment of the present invention will be described in detail below in conjunction with the accompanying drawings: In this embodiment, a winding machine is used to wind the superconducting wire to the coil frame to form a single double cake superconducting coils. After the winding of the four double-cake coils is completed, the wires drawn from each double-cake coil are welded on the terminals 8 between the coils to assemble a superconducting coil body, and the ends of the four superconducting coils 7 are connected to the superconducting coil terminals. 9 welded together. The superconducting coil body that has been wound and welded is assembled in the coil chamber 5, the lower part of the superconducting coil body is cushioned with an insulating support plate (not shown in the figure) between the chambers, and the magnet current terminal is connected by a countersunk screw. The support is fixed on the insulating support plate for fast connection, and the insulating support plate plays the role of preventing short circuit and heat leakage. In addition to placing the superconducting coil 7 , the inner area of the coil chamber 5 also serves as a circulation channel for cooling medium. In this embodiment, supercooled liquid nitrogen is used as cooling the superconducting coil 7 . The electrical connector 2 is connected to the superconducting coil terminal 9 through screws, and the electrical connector 2 is fixed to the partition through an insulating gasket. The partition does not function as an isolation seal, and is only used as a supporting structure between the electrical connector 2 and the liquid nitrogen pipeline 10 , wherein the cavity where the coil is located is connected to the cavity of the extension section. The electrical connector 2 is connected to the electric vacuum feedthrough 1 through a flexible connection. In this embodiment, a copper braid is used as the flexible connection, and the two ends of the copper braid are respectively welded to the electrical connector 2 and the electric vacuum feedthrough 1 together. The copper braid has a certain stretchability, which can relieve the thermal stress caused by the mismatch of thermal expansion coefficients of various materials during the cooling process of the magnet. The connection between the liquid nitrogen channel 10 and the partition plate 13 is in the form of welding, wherein part or all of the liquid nitrogen pipeline is connected flexibly. The expansion and contraction ability of the magnet can relieve the thermal stress caused by the mismatch of the thermal expansion coefficient of each material during the cooling process of the magnet. The electric vacuum feedthrough 1 is vacuum connected to the front end cover 12 of the outer wall of the coil annular chamber. In this embodiment, a KF flange connection is adopted. The liquid nitrogen pipeline 10 is connected to the front end of the coil annular chamber by vacuum connection. In this embodiment, A solder connection is used. The coil annular chamber protrudes from the shell chamber to form the front end of the coil annular chamber. The liquid nitrogen pipeline 10 and the electric vacuum feedthrough 1 are both sealed and connected to the front end of the coil annular chamber. The sealing surfaces are all located outside the magnet, and the sealing is simple. , Leak detection operation is easy to realize, vacuum problems can be repaired in time, and the operation stability is high. The interior of the extension section of the coil chamber can be filled with foam and other materials, on the one hand to prevent liquid nitrogen from entering the area; on the other hand, it plays a role of heat insulation, increasing the thermal resistance between liquid nitrogen and the front surface of the coil chamber, and reducing heat leakage. In this embodiment, the filling material is rigid foam. The vacuum flange port 3 is connected to the outer wall of the vacuum chamber 4 by welding. In this embodiment, the vacuum flange port 3 is used for vacuuming to reduce the absolute pressure between the outer vacuum chamber 4 and the coil chamber 5, thereby reducing Heat leak.

Those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present invention, rather than as a limitation to the present invention, as long as they are within the scope of the spirit of the present invention, appropriate changes made to the above embodiments and changes all fall within the scope of protection of the present invention.

The compact superconducting magnet device with a room temperature magnetic field cavity proposed by the present invention has the following working principle:

The compact superconducting magnet device with a room temperature magnetic field cavity of the present invention is mainly composed of a coil chamber, a vacuum chamber, a superconducting coil, a liquid nitrogen pipeline, an electric channel and the like. When working, liquid nitrogen is input into the coil chamber 5 through a liquid nitrogen pipeline 10, and liquid nitrogen is output through another liquid nitrogen pipeline, and the liquid nitrogen flows through the coil chamber 5 to cool the superconducting coil 7, reducing the superconducting coil 7 to 77K And below, at this time the superconducting coil 7 has superconducting properties. During operation, because the entire coil chamber 5 is at a relatively low temperature, it is necessary to evacuate the thin-layer space between the coil chamber and the vacuum chamber to reduce heat leakage from the external environment to the liquid nitrogen chamber. When working, the superconducting coil 7 is energized through the electric feedthrough 1 and the electrical connector 2, and the superconducting coil 7 can excite a magnetic field in the state of being energized, and the main magnetic field space is located in the cavity at the center of the superconducting coil 7. The heat insulation effect of the vacuum chamber can keep the magnetic field space in a room temperature environment, so the device provides a room temperature magnetic field cavity.

The liquid nitrogen pipeline in the superconducting magnet device of the present invention can adopt corrugated pipes in whole or in part, and the corrugated pipes have a certain expansion and contraction ability, which can alleviate the thermal stress caused by the mismatch of thermal expansion coefficients of various materials during the cooling process of the magnet.

Copper braids can be used in whole or in part for the electrical connectors. The copper braids have a certain stretching ability, which can relieve the thermal stress caused by the mismatch of thermal expansion coefficients of various materials during the cooling process of the magnet.

Claims (1)

1. A compact superconducting magnet device with a room temperature magnetic field cavity, characterized in that, the superconducting magnet device comprises a shell and a superconducting coil with a vacuum chamber; In the coil chamber in the shell of the chamber, the outer wall of the shell with the vacuum chamber is provided with a vacuum flange port, and the vacuum chamber is sealed with the vacuum pump through the vacuum flange port, and the vacuum chamber of the shell An insulating pad is provided in the middle; the coil chamber is connected with the liquid nitrogen pipeline, and the liquid nitrogen passing through the liquid nitrogen pipeline flows through the coil chamber to cool the superconducting coil, so that the superconducting coil has superconducting performance; inter-coil terminals are provided between the coils of the superconducting coil, and the superconducting coil is flexibly connected to the electric vacuum feedthrough through the superconducting coil terminal and the electrical connector, through the electric vacuum feedthrough and the electric vacuum feedthrough The electrical connector energizes the superconducting coil, and the superconducting coil excites a magnetic field in the energized state, and the magnetic field space is located in the cavity at the center of the superconducting coil; the coil chamber extends out of the vacuum chamber The shell is used to form the front end of the coil chamber outside the vacuum chamber, wherein the coil chamber communicates with the extension cavity; the liquid nitrogen pipeline passes through the front end of the coil chamber and connects with the coil The front end of the chamber is sealed and connected, the electric vacuum feedthrough passes through the front end of the coil chamber to connect with the electrical connector in the coil chamber, the electric vacuum feedthrough is connected to the front end of the coil chamber All or part of the liquid nitrogen pipeline adopts bellows to relieve the thermal stress of the superconducting magnet device during operation; all or part of the electrical connector adopts copper braid to relieve the superconducting magnet device Thermal stress during work.

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