JPS5855648B2 - Superconducting coil manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a large-sized superconducting coil used in nuclear fusion devices, energy storage devices, etc.

The use of superconducting coils as a component of energy storage devices and magnetic field generators for nuclear fusion reactors is being considered, but the size of superconducting coils is gigajoule (Gj=lO9=) or larger.

FIG. 1 is a partially cutaway perspective view of a pancake-shaped superconducting coil, which is a type of large-sized superconducting coil. It has a structure in which a plurality of superconducting wires are stacked and fixed in a winding frame 5 via an interlayer spacer 4, and the superconducting wire 2 is electrically insulated both between turns and between layers by the interturn spacer 3 and the interlayer spacer 4E. The interlayer spacer 4 forms a gap 6 through which a cooling medium such as liquid helium flows.

This gap 6 has the role of allowing air bubbles of the cooling medium generated on the surface of the superconducting wire 2 to escape, and the role of supplying the cooling medium.

FIG. 2 is a cross-sectional view of a disk-shaped superconducting coil, which is a type of large-sized superconducting coil. In this superconducting coil 1, a plate-shaped holding member γ made of metal or an insulator has one coil groove 8 on both sides. A plurality of superconducting disks 200 formed by accommodating the superconducting wire 2 in one coil groove are stacked and assembled by tightening with bolts 9 and nuts 10.

The disk-shaped superconducting coil 1 can be a circular coil 1 shown in FIG. 3 a1 similar to the pancake-shaped superconducting coil shown in FIG.
The figure shows a COD type coil 1.

The most suitable superconducting wire 2 having a large current capacity for use with one of these large superconducting coils is a solder-type superconducting wire.

FIGS. 4a and 4b are perspective views of a solder-type superconducting wire, in which a normal-conducting metal base material 111, a groove 121 cut out, an aggregate 14 of multiple superconducting strands 13 are soldered to a metal adhesive such as pbSn, etc. ) 151.

The normally conductive metal base material 11 is made of copper or aluminum, which has an electrical resistivity at an extremely low temperature (for example, liquid helium temperature of 4.2 K), and copper or aluminum is often used at present.

The superconducting wire 13 may be a superconductor itself such as Nb-Ti or Nb3Sn, but it may also be a superconductor coated with copper or aluminum, or a normal conductive metal such as copper with multiple superconducting filaments embedded in it. An ultrafine multicore twisted superconducting wire in which the superconducting filament is twisted and embedded in a normal conducting metal may be used.

As shown in the perspective view of FIG. One flat aggregate 14 as shown in Figure b1 can be easily obtained.

Although the above-mentioned aggregate 14 is a band-shaped twisted wire, a single band-shaped braided wire may be used instead of the band-shaped twisted wire.

Note that the superconducting wire 21 in FIG.
J) Side surface 1 of a rectangular normal conductive metal base material 11 without grooves
A superconducting wire in which the superconducting strand assembly 14 is fixed with solder can also be used.

Next, the first method of manufacturing a conventional superconducting coil will be described.

The superconducting wire 2 produced by fixing the superconducting wire 13 in the groove 121 of the normal conducting metal base material 11 with the solder 15
is wound into the shape shown in FIG. 3 to form the superconducting coil 1.

The superconducting wire is bent flatly during coil winding in the pancake-shaped superconducting coil shown in FIG. 1, and etch-wise in the disk-shaped superconducting coil shown in FIG.

The superconducting coil 1 used in energy storage devices and nuclear fusion reactors is a gigantic one with an energy of gigajoules or more, and the superconducting wire 2 wound around it is energized with a large current, for example 30,000 amperes. Large dimensions that can be used, such as outer dimensions of 1010mm x 60. It is something that has.

When winding the superconducting wire 2, which is one size larger, in the shape shown in Fig. 3, the minimum bending radius of the coil should be set to, for example, 1.
If m, a strain of 0.5% in the flat width and 3% in the etch width occurs in the superconducting wire 21.

Especially in the case of edge-wise bending, the distortion is large.

This distortion of the superconducting wire at the same time as the coil winding reduces the superconducting current capacity of the superconducting wire 13, which is a basic structural element of the superconducting wire 20, by a large width, and as a result, the magnetic field created by the superconducting coil 10 becomes larger than the designed value. The width may be reduced by 1.

In particular, when the superconductor is a compound such as Nb3Sn, the superconducting properties are significantly deteriorated.

This invention was made in order to eliminate the drawbacks of the conventional method of manufacturing superconducting coils as described above.
After winding only the normal conductive metal base material 11, which is a component of It is possible to provide a large superconducting coil that is used in one furnace and does not have a decrease in superconductivity.

FIG. 6 shows an embodiment of the method for manufacturing a superconducting coil according to the present invention, in which the normal conductive metal base material 11 is bent into a coil shape as shown in FIG. After fixing the coil groove 81 provided in member T1, as shown in FIG.
1) This superconducting strand assembly 14 is fixed in the groove 121 of the normal conductive metal base material 11 with solder (1), thereby forming the disk-shaped superconducting coil 1.

As described above, according to the present invention, it is impossible to generate distortion caused by the first winding after the superconducting wire 13 is fixed to the normal conductive metal base material 111, so that the superconducting coil does not deteriorate the superconducting properties. can be provided.

In the above superconducting coil, the normal conducting metal base material 11 is formed into a single coil shape and then the superconducting strand assembly 14 is fixed thereon. Superconducting wire 2 remade by fixing the wire assembly 14
After that, it is possible to form a superconducting coil by completely twisting the coil into a single coil shape.

In this case, almost no distortion occurs due to the bending of the superconducting wire 2).

Moreover, according to this method 1, it is also possible to fix one superconducting strand assembly 14 on both sides of the normal conducting metal base material 11 as shown in FIG. Coils can also be made.

As described above, according to the present invention, the superconducting wire assembly is fixed after the normal conductive metal base material is wound once into a coil shape, so that the characteristics of the superconducting coil are not deteriorated. Coils can be manufactured.

[Brief explanation of drawings]

Figure 1 is a partially cutaway view of a pancake-shaped superconducting coil, Figure 2
The figure is a cross-sectional view of a disk-shaped superconducting coil, Figure 3 is a perspective view showing the shape of the superconducting coil, Figure 4 is a perspective view showing the completed state as a conventional solder-type superconducting wire, and Figure 5 is a stranded wire and strip-shaped twisted wire. FIG. 6, a perspective view showing lines, is an embodiment of the superconducting coil manufacturing method of the present invention. In the figure, 1 is a superconducting coil, 2 is a superconducting wire, 11 is a normal conducting metal base material, 12 is a groove, 13 is a superconducting wire, 14 is a superconducting wire assembly, and 15 is a solder. In addition, in the figure, the same reference numerals indicate the same minutes. or equivalent portion

Claims (1)

[Scope of Claims] 1. A method comprising the steps of: winding a normal conducting metal base material into a coil shape; and fixing a superconducting strand to one surface of the normal conductive metal base material wound into a coil shape with solder. A method for manufacturing superconducting coils. 2. Step of bending a normal conductive metal base material into a substantially coil shape, the surface 1 of the normal conductive metal base material bent into a substantially coil shape.
A method for producing a superconducting coil comprising the steps of fixing the superconducting strands with solder to form a substantially coil-shaped superconducting wire, and winding the substantially coil-shaped superconducting wire once into a coil shape.