JPH0636625A - Superconductor - Google Patents

Abstract

PURPOSE:To enable a superconductor of steady conductive state to easily return to superconducting state by restraining a current flow across stabilizing materials, while a part of a boundary between the materials being divided with an insulation material. CONSTITUTION:An insulation material 8 such as polyamide resin is laid at a boundary between copper 1 and aluminum 4 as stabilizing materials. When a superconductor turns into steady conductive state due to an instantaneous temperature rise, electrical current flows across the aluminum 4 or copper wires 4 and 5 having low electrical resistance, and not across a superconducting wire 2. Consequently, electrical field is generated within the cross section of the superconductor, due to the interaction of current and magnetic field. In this case, the copper 1 and the aluminum 4 are electrically isolated from each other with an insulation material 8 and, therefore, no current is generated within the section, thereby reducing the calorific value of generated heat. As a result, the superconductor returns to superconducting state and allows electrical current to flow as original.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting conductor including a plurality of types of stabilizing materials.

[0002]

2. Description of the Related Art FIG.
(Year) Spring Low Temperature Engineering / Superconductivity Society Proceedings page 48 "is a cross-sectional view showing a conventional superconducting conductor.
Reference numeral 1 is copper as a stabilizing material, 2 is a superconducting element wire, 3 is a superconducting twisted wire formed by twisting a number of superconducting element wires 2, 4 and 5 are aluminum and copper as a stabilizing material, and 6 is Composite metal as a stabilizing material consisting of aluminum and copper,
Reference numeral 7 is lead-tin solder that joins these materials.

In such a structure, when the superconducting conductor is cooled to a cryogenic temperature of about -267 ° C. by a coolant such as liquid helium, the superconducting element wire 2 is in a superconducting state, so that current can flow without resistance loss. You can Also, by utilizing this property, a magnet that generates a magnetic field by winding a superconducting conductor is manufactured, and when a current is passed through the superconducting conductor,
Electromagnetic force is generated by the external magnetic field and the current flowing through the superconducting conductor itself, and if the conductor moves for this reason, heat may be generated due to friction at that time, and the temperature of the superconducting conductor may momentarily rise to the normal conducting state. is there.

At this time, the current does not flow through the superconducting element wire 2 and aluminum 4 or copper 1 and 5 having a small electric resistance.
Flowing through. At this time, since aluminum 4 or copper 1 and 5 are normally conductive substances, they are inevitable to generate heat due to resistance loss. In that case, the superconducting conductor is brought into a superconducting state again and can be energized as before.

In the above description, the case where a normal state is generated in the superconducting conductor due to the electromagnetic force due to the external magnetic field and the current flowing in the superconducting conductor has been described. A normal state may occur due to mechanical disturbance, and in this case as well, the same operation causes the superconducting conductor to be in the superconducting state again, and the current can be supplied as before.

Actually, the electric resistivity of high-purity aluminum at cryogenic temperature is 1 × 10 ^-11 Ωm, and the electric resistivity of electrolytic copper is very small, 1 × 10 ^-10 Ωm, and a suitable conductor is used. With the cross-sectional area, even if the superconducting conductor is once in the normal state as described above, it returns to the superconducting state.

[0007]

Since the conventional superconducting conductor is constructed as described above, it is possible to pass an electric current in a cooled state without electric resistance loss, but there is a magnetic field applied from the outside. In this case, when the temperature of the superconducting conductor rises to the normal state due to some disturbance and a current flows in the stabilizing material, the interaction between the current flowing in the stabilizing material and the magnetic field causes Electric field is generated (Hall effect).

At this time, when all the same metals are used as the stabilizing material, a uniform electric field is generated and no particular trouble is caused, but if the stabilizing material is different. Since the generated magnetic fields are also different, a current is circulated in the cross section of the superconducting conductor, and as a result, there is a problem that the amount of heat generation increases to the extent that the refrigerant cannot handle it.

The present invention has been made to solve the above problems, and reduces the heat generation amount (electrical resistance loss) in the normal state as much as possible and at the same time sets the superconducting conductor into the normal conducting state. It is an object of the present invention to provide a superconducting conductor capable of easily returning to the superconducting state of.

[0010]

According to a first aspect of the present invention, there is provided a superconducting conductor, wherein a part of a boundary between the stabilizing materials is an insulating material which blocks a current flow between the stabilizing materials or the stabilizing material. It is configured by partitioning with a metal having a high resistivity that suppresses the flow of current between the chemicals.

A superconducting conductor according to a second aspect of the present invention is a metal having a high resistivity that suppresses a current flow between the stabilizing materials along the entire circumference of the boundary between the stabilizing materials. It is composed by dividing it.

[0012]

In the superconducting conductor according to the first aspect of the present invention, the circulating current generated in the cross section of the superconducting conductor by the insulating material or the metal having high resistivity provided at the boundary between the stabilizing materials. Is blocked or significantly suppressed, the amount of heat generated when the superconducting conductor is in the normal state is extremely small, and therefore the refrigerant is easily returned to the superconducting state.

In the superconducting conductor according to the second aspect of the present invention, the rigidity of the superconducting conductor can be further improved by the insulating material or the metal having a high resistivity provided at the boundary between the stabilizing materials. Can be improved.

[0014]

【Example】

Example 1. 1 is a sectional view of a first embodiment of a superconducting conductor according to claim 1 of the present invention.
The same parts and corresponding parts as those of the conventional example are designated by the same reference numerals, and the description thereof will be omitted. Reference numeral 8 is an insulating material that insulates the electrical connection between the copper 1 and the aluminum 4.

The insulating material 8 is interposed at the boundary between the copper 1 and the aluminum 4, and the insulating material 8 blocks the current flow between the copper 1 and the aluminum 4. As the insulating material 8, a material that can sufficiently withstand the temperature at the time of manufacturing the superconducting conductor, such as polyamide resin or ceramics, is used.

In such a structure, when the superconducting conductor is cooled to a cryogenic temperature of about -267 ° C. by a coolant such as liquid helium, the superconducting element wire 2 is in a superconducting state, so that current can flow without resistance loss. You can Also, by utilizing this property, a magnet that generates a magnetic field by winding a superconducting conductor is manufactured, and when a current is passed through the superconducting conductor,
Electromagnetic force is generated by the external magnetic field and the current flowing in the superconducting conductor itself, and when the conductor moves due to this, heat is generated due to the friction at that time, and the temperature of the superconducting conductor may momentarily rise to the normal conducting state. is there.

At this time, the current does not flow through the superconducting element wire 2 but through the aluminum 4 or copper wires 1 and 5 having a low electric resistance. Since aluminum 4 or copper 1 and 5 are normally conductive substances, they are inevitably heated by resistance loss. Further, since a current flows through the copper 1 and 5 and the aluminum 4 in the magnetic field, an electric field is generated in the cross section of the superconducting conductor due to the interaction between the current and the magnetic field (Hall effect).

However, since the insulating material 8 is interposed at the boundary between the copper wire and the aluminum 4 and the insulating material 8 electrically insulates the copper 1 and the aluminum 4, no current is generated in the cross section. The amount of heat generated is smaller than that without an insulator. If the amount of heat at this time can be removed by the refrigerant and the temperature of the superconducting conductor is such a small amount that it can return to the superconducting state, the superconducting conductor becomes the superconducting state again and can be energized as before, and therefore, the cooling state. With this, a stable current can be passed.

When there is a magnetic field applied from the outside, the temperature of the superconducting conductor rises to a normal state due to some disturbance, and a current flows in the copper 1, 5 and aluminum 4 as a stabilizing material. At this time, even if an electric field is generated in the cross section of the superconducting conductor (Hall effect) due to the interaction between the current flowing through the stabilizing material and the magnetic field, the insulating material 8 is formed at the boundary between the copper 1 and the aluminum 4 as the stabilizing material. Since it is interposed, no current is generated in the cross section of the superconducting conductor, and therefore, there is no heat generation, so that stability is not reduced.

Example 2. FIG. 2 shows a second embodiment of the superconducting conductor according to the first aspect of the present invention. In the figure, the same parts as those of the first embodiment and the corresponding parts are designated by the same reference numerals and their description is omitted. Is omitted. Reference numeral 9 is aluminum as a stabilizing material, and 10 is an insulating material for insulating electrical connection between the aluminum 9 and the copper 1 and between the aluminum 9 and 9.

A plurality of aluminums 9 are vertically and horizontally symmetrically provided around the superconducting wire 2, and the insulating material 10 is used.
Are interposed between the aluminum 9 and the copper 1 and at the boundaries between the adjacent aluminum 9 and 9, respectively. Further, the insulating material 10 is vertically and horizontally symmetrically installed around the superconducting element wire 2 like the aluminum 9.

According to this embodiment, even if there are a plurality of aluminums 9 in the cross section of the superconducting conductor, if the insulating material 10 is provided at the boundary between the aluminum 9 and the copper 1 and the adjacent aluminums 9 and 9. The same effect as the first embodiment is obtained. Moreover, since the aluminum 9 and the insulating material 10 are symmetrically arranged in the cross section of the superconducting conductor, the bending characteristics do not change depending on the bending direction of the superconducting conductor when the coil is wound, and the bending process is easy. effective.

Example 3. FIG. 3 shows a third embodiment of the superconducting conductor according to the first aspect of the present invention. In the figure, the same parts as those of the first embodiment and the corresponding parts are designated by the same reference numerals and their description is omitted. Is omitted. Reference numeral 11 is a metal having a high resistivity that suppresses the current flow between the aluminum 4 and the copper 1 as much as possible. As the metal material 11 having a high resistivity, for example, a copper-nickel alloy having an electrical resistivity at extremely low temperatures of about 1000 times that of copper is used.

According to this embodiment, the current in the cross section of the superconducting conductor can be made substantially zero, and the same effect as using the insulating material is obtained, and the superconducting conductor is joined by the lead-tin solder. And the rigidity of the superconducting conductor can be increased. The metal material having a high resistivity is not limited to the copper-nickel alloy, and the same effect can be obtained even if stainless steel having a property of high electrical resistivity is used. If stainless steel is used, there is an effect that a coil constituted by a superconducting conductor can have good magnetic field accuracy.

Example 4. FIG. 4 shows a first embodiment of the superconducting conductor according to the second aspect of the present invention. In the figure, the same parts as those of the first embodiment and the corresponding parts are designated by the same reference numerals, and The description is omitted. Code 12
Is a metal material having a high resistivity that suppresses the flow of current between the aluminum 4, the superconducting element wire 2 and the copper 1 as much as possible. The metal 12 having a high resistivity is interposed so as to completely separate the periphery of the aluminum 4 from the superconducting element wire 2 and the copper 1.

According to this embodiment, since the metal material 12 having a high resistivity is installed so as to completely surround the periphery of the aluminum 4, there is an effect that the rigidity of the superconducting conductor can be further enhanced. Since the length of the superconducting conductor is sufficiently long as compared with the cross-sectional dimension of the superconducting conductor, the metal 1 having a high resistivity all around the aluminum 4 as the stabilizing material.
Even if 2 is interposed, there is no problem in transferring the current from the superconducting element wire to the aluminum 4 when the superconducting conductor is in the normal state.

Example 5. FIG. 5 shows a second embodiment according to the second aspect of the present invention. In the drawing, the same parts and corresponding parts as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. To do. Reference numeral 13 is a metal material having a high resistivity that suppresses the flow of current in the cross section of the superconducting conductor as much as possible. The metal 13 having a high resistivity is installed in the cross section of the copper 1 so as to block the current flow in the vertical direction in the figure.

According to this embodiment, it is possible to secure the electrical connection between the aluminum 4 as the stabilizing material and the superconducting element wire 2 while suppressing the current flow in the cross section of the superconducting conductor to ensure the stability. effective.

Example 6. FIG. 6 shows a third embodiment according to the second aspect of the present invention. In the drawing, the same parts and corresponding parts as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. To do. Reference numeral 14 is aluminum as a stabilizing material, and 15 is a metal having a high resistivity that suppresses a current flow between the aluminum 14 and the superconducting element wire 2 and the copper 1 as much as possible.

The aluminum 14 is formed in a small cross section and a plurality of aluminum 14 are installed. In addition, the metal 15 having a high resistivity
Are installed around each aluminum 14 so as to completely surround the aluminum 14. According to this embodiment, since the aluminum 14 and the metal material 15 having a high resistivity have small cross sections, the single length of the component can be made long, and a long superconducting conductor can be manufactured.

[0031]

The superconducting conductor according to claim 1 of the present invention is constructed as described above, and an insulating material for blocking a part of the boundary between the stabilizing materials from the flow of current between the stabilizing materials. Or, the current flowing in the cross section of the superconducting conductor is suppressed even if the superconducting conductor is temporarily in a normal state because it is separated by a metal having a high resistivity, which suppresses the current flow between the stabilizing materials. Since there is no or very little, there is an effect that a stable superconducting conductor can be obtained with very little heat generation due to resistance loss.

According to the superconducting conductor of the second aspect, the entire circumference of the boundary between the stabilizing materials is separated by a metal having a high resistivity, which suppresses the current flow between the stabilizing materials. Therefore, in addition to the above effects, there is an effect that a superconducting conductor having higher rigidity can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a superconducting conductor according to the first aspect of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the superconducting conductor according to the first aspect of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the superconducting conductor according to the first aspect of the present invention.

FIG. 4 is a sectional view showing a first embodiment of a superconducting conductor according to claim 2 of the present invention.

FIG. 5 is a sectional view showing a second embodiment of the superconducting conductor according to the second aspect of the present invention.

FIG. 6 is a sectional view showing a third embodiment of the superconducting conductor according to the second aspect of the present invention.

FIG. 7 is a cross-sectional view showing a conventional superconducting conductor.

[Explanation of symbols]

 1 Copper (Stabilizing Material) 4 Aluminum (Stabilizing Material) 5 Copper (Stabilizing Material) 8 Insulating Material 9 Aluminum (Stabilizing Material) 10 Insulating Material 11 Metal with High Resistivity 12 Metal with High Resistivity 13 High Metal with resistivity 14 Aluminum (stabilizer) 15 Metal with high resistivity

Claims (2)

[Claims] 1. In a superconducting conductor including a plurality of types of stabilizing materials, a part of the boundary between the stabilizing materials is
A superconducting conductor characterized by being separated by an insulating material that blocks a current flow between the stabilizing materials or a metal having a high resistivity that suppresses a current flow between the stabilizing materials. 2. In a superconducting conductor including a plurality of types of stabilizing materials, the entire circumference of the boundary between the stabilizing materials is
A superconducting conductor characterized by being separated by a metal having a high resistivity, which suppresses a current flow between the stabilizing materials.