JPS59208811A - Superconductive coil - Google Patents

Abstract

PURPOSE:To improve the stability of a superconductive coil by forming an irregular surface on the contacting surface with an adjacent superconductor, thereby reducing the movement of the superconductor due to an electromagnetic force. CONSTITUTION:Superconductive conductors 1, 2 which are wound adjacent to each other are buried in a copper of aluminum base material 6 to stabilize a plurality of superconductive wires 3, and projections 4, 4' and recesses 5, 5' are formed as pairs radially of the winding on the wound conductors 1, 2. When the conductor 1 is already wound and the conductor 2 disposed on the outer layer is wound, the conductor 2 is wound so that the projection 4' of the conductor 2 is engaged with the recess 5 of the conductor 1. Further, an insulator 7 such as Mylar or fiber-reinforced plastic is inserted between the recess 5 and the projection 4' and between the conductors 1 and 2 disposed oppositely, thereby improving the stability of the coil.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a superconducting coil, and more particularly, to a superconducting coil suitable for use in a large-sized coil such as a superconducting poloidal coil for a nuclear fusion reactor.

[Background of the invention]

Generally, a superconducting coil is constructed by winding a superconducting conductor in which multiple superconducting wires are embedded in a stabilizing material, and when this superconducting coil is excited, a large electromagnetic force acts on the superconducting conductor. Taking a circular superconducting coil as an example, when excited, there is an electromagnetic force (hoop force) that tends to expand in the radial direction, and an electromagnetic force (hoop force) that tends to contract in the center in the axial direction.
compressive force) acts. In particular, as the superconducting coil becomes larger and the generated magnetic field and operating current become larger, this electromagnetic force becomes more beautiful. When electromagnetic force is applied to a superconducting conductor, the superconducting conductor moves easily, the training effect of superconducting coils,
This becomes an unstable factor called the degradation effect.

In addition, although a conductor support material is used to prevent the movement of the superconducting conductor, macroscopic and microscopic cracks occur at the contact surface between the supporting material and the superconducting conductor, resulting in heat generation due to frictional heat. It will become a hotspot. Normally, superconducting coils are cooled with liquid helium, but even when cooled with a coolant such as liquid helium, this heat generation is more dominant. If the temperature exceeds the superconducting temperature (critical temperature), a normal conduction transition (destruction of the superconducting state) will occur in that part, which is not preferable because there is a risk that the entire superconducting coil will undergo a normal conduction transition. In particular, in superconducting applied equipment that operates in pulses, such as superconducting poloidal coils for nuclear fusion reactors, the above-mentioned tendency becomes even more remarkable because electromagnetic force is applied repeatedly.

[Purpose of the invention]

The present invention has been made in view of the above points, and its object is to provide a stable superconducting coil by reducing the movement of a superconducting conductor due to electromagnetic force without providing a special support member.

[Summary of the invention]

The present invention forms uneven portions on opposing contact surfaces of adjacent superconducting conductors that come into contact with each other during winding of a superconducting conductor formed by embedding a plurality of superconducting wires in a stabilizing material, and the uneven portions are fitted into each other. The desired purpose is achieved by configuring the coil in a winding manner.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail based on embodiments of the drawings.

FIG. 1 shows a part of a winding portion as an embodiment of a superconducting coil according to the present invention. As shown between the cores, superconducting conductors 1 and 2 are wound adjacently, and a plurality of superconducting wires 3 are embedded in a copper or aluminum base material 6 for stabilization. The superconducting conductors 1 and 2 to be rotated are each formed with a pair of convex portions 4 and 4' and a concave portion 5.degree. 5' in the radial direction of the winding. Now, the superconducting conductor 1 has already been wound, and when winding the superconducting conductor 2 located on the outer layer, the superconducting conductor 2 is wound so that the convex part 4' of the superconducting conductor 2 fits into the concave part 5 of the superconducting conductor 1. Furthermore, an insulator 7 such as mylar or fiber-reinforced plastic is inserted between the recess 5 and the protrusion 4' and between the superconducting conductors 1 and 2 facing each other. Then, this process is repeated a predetermined number of times to wind the superconducting conductor to form a superconducting coil. In this way, in the superconducting coil of this example, since the recesses and protrusions provided on each superconducting conductor fit into each other, the electromagnetic force acting in the radial direction of the winding of the superconducting coil and in the direction of the center of the coil axis It is robust against movement of the superconducting conductor due to force. Therefore, even if electromagnetic force is applied, the movement of the superconducting conductor is reduced, and the stability of the superconducting coil is improved.

In the above embodiments, mylar and fiber reinforced plastic were used as examples of insulators, but if a material with excellent adhesive properties and insulation properties such as curable epoxy resin is used,
Furthermore, it goes without saying that the superconducting conductors 1 and 2 are solidly integrated and a stable superconducting coil can be obtained.

FIG. 2 shows an example in which single pancake coils 8 are laminated in the axial direction as a superconducting coil having the above-described configuration, and shows the connection state between the pancake coils at that time.

By soldering the adjacent winding ends of the single pancake coil 8 having the configuration of the above embodiment with a superconducting conductor, copper wire, etc., as between the cores, a pancake connection part 9 is formed. B. It is easy to fit the concave portion and the convex portion of the superconducting conductor and wind the superconducting conductor to form a superconducting coil. Furthermore, in the double pancake wound coil, some of the concave and convex portions of the superconducting conductor located near the winding transition area are processed in advance.
It is sufficient that the wire can be transferred smoothly between the wires. In either case, insulating spacers (not shown) are partially inserted between the pancake coils to form cooling channels 10 into which the refrigerant can easily enter.

FIG. 3 shows another embodiment of the present invention, in which it is applied to a forced cooling type superconducting coil, in which a refrigerant flow path 11 is formed approximately in the center of the cross section of a superconducting conductor 12, and its opposing axes are An uneven portion is also provided on the directional surface, and the superconducting conductor 12 is laminated in the axial direction by fitting the uneven portion with an insulator interposed therebetween.

With this configuration, liquid helium, which is a refrigerant, is forcibly circulated through the refrigerant channel 11 in the superconducting conductor 12. There is no need to provide a cooling channel between the superconducting conductors 12, and by providing irregularities in the winding direction and lamination direction of the superconducting conductor 12 and fitting these together, a superconducting coil that is more robust against electromagnetic force can be created. I can do it.

〔Effect of the invention〕

According to the superconducting coil of the present invention described above, uneven portions are formed on the opposing contact surfaces of adjacent superconducting conductors that come into contact with each other during winding of a superconducting conductor formed by embedding a plurality of superconducting wires in a stabilizing material. However, since the concave and convex portions are wound together by fitting each other, there is no need to provide a special support member.
By simply fitting the uneven portions together, the movement of the superconducting conductor due to electromagnetic force can be reduced, and a stable superconducting coil of this type can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a fitted state of superconducting conductors employed in an embodiment of the superconducting coil of the present invention, and Fig. 2 is a single pancake coil formed by winding the superconducting conductor of Fig. 1. A cross-sectional view showing the state of the connection between the pancake and the pancake, the third
The figure is a perspective view showing a fitted state of superconducting conductors for forced cooling in another embodiment of the present invention. 1.2.12...Superconducting conductor, 3...Superconducting wire, 4
゜4'... Convex portion, 5,5'... Concave portion, 6... Stabilizing base material, 7... Absolutely R object, 8... Single pancake coil, 9... Pancake Connection part, 10... Cooling channel, 11... Refrigerant flow path.

Claims (1)

[Scope of Claims] 1. In a superconducting coil constructed by winding a superconducting conductor formed by embedding a plurality of superconducting wires in a stabilizing material multiple times, an adjacent superconductor that comes into contact when the superconducting conductor is wound A superconducting coil characterized in that a concave and convex portion is formed on opposing contact surfaces of the coils, and the concave and convex portions are fitted into each other and wound. 2. The superconducting coil according to claim 1, wherein the uneven portions are fitted with an insulator interposed therebetween. 3. The superconducting conductor in which the uneven portions are fitted together is wound multiple times to form a pancake-shaped coil, and the pancake coils are stacked in the axial direction, and cooling channels are provided between the pancake coils. A superconducting coil according to claim 1 or 2, characterized in that the superconducting coil is formed with: 4. Concave and convex portions are also formed on opposing axial surfaces of the superconducting conductor, and the concave and convex portions are fitted to stack the superconducting conductors in the axial direction, and the cross section of the superconducting conductor has a refrigerant passage approximately in the center. A superconducting coil according to claim 1 or 2, characterized in that the superconducting coil is provided with: