JPS60262089A - Toroidal coil for nuclear fusion device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toroidal coil for a nuclear fusion device, and particularly to an improvement of its can.

[Prior art]

FIG. 1 is a cross-sectional view of the main parts of a conventional nuclear fusion device, including a single loidal coil, a voloidal coil, and three voloidal coils. It is composed of X, J, etc. The vacuum vessel l has a doughnut-like cross section with a precise i-shape, and this nuclear fusion device, in which the plasma 3 is confined by □ magnetic fields in three directions, uses a voloidal coil 3. A vacuum vessel l and a voloidal coiler are respectively arranged around two axes on the central axis of the toroidal coil, and a plurality of toroidal coils are arranged to radiate in the radial direction so as to be orthogonal to these devices. □It has been carefully arranged and assembled.

As shown in Figure 2, a single toroidal coil supports the conductor 6 through which the sum current flows, and the huge electromagnetic force (centripetal force and hoop force) that acts on the toroidal coil when current is passed through this conductor base. It is composed of a can 7. This can 7 is made of a material that is durable enough to withstand a variety of environments in order to support a huge electromagnetic force. Further, when the conductor 6 is made of a superconducting conductor, the can also functions as a container for storing liquid helium.

Next, the operation of the toroidal coil l' of the nuclear fusion device having the above configuration will be explained. Now, a tokamak type.

A current is passed through the conductor 6 as a discharge to generate a magnetic field in the ψ direction. Next, voloidal coil 3. The electric current flowing through the tube is changed over time to create an electric field in nine directions, generate a plasma current, confine the plasma J, and heat it.

By the way, for the cank, Boroidarcoi, Le 31V,
In plasma, a magnetic field is generated by the flow, and as the magnetic field changes over time, eddy currents are generated.Especially in the can, the part on the two-axis side of the single toroidal coil is caused by the voloidal coils 3 and 41. The rate of change of the magnetic field in the two axial directions increases, and as shown in FIG. 2, larger eddy currents are generated compared to other parts. In this way, the toroidal coil of this fusion device, combined with the fact that the can 7 is made of thick non-magnetic steel, causes a large eddy current to flow through the can.
As a result, the interaction between this eddy current and an external magnetic field increases the electromagnetic force exerted on the can and the heat generated by the can itself. Particularly, when the conductor 6 is made of a superconducting conductor and the can 7 also functions as a helium liquid container, the heat generated by this eddy current has become a big problem in terms of cooling.

[Summary of the invention]

This invention was made for the purpose of eliminating the above-mentioned drawbacks, and was made on the inner surface of a single toroidal coil.

To provide a toroidal coil for a nuclear fusion device, which increases effective resistance to eddy currents, reduces eddy currents, and reduces eddy current loss and electromagnetic force through a simple configuration of forming slits. It is.

[Embodiments of the invention]

Hereinafter, one embodiment of the toroidal coil of the nuclear fusion device of the present invention will be described with reference to FIGS. 3 to 3. 3 is a cross-sectional view of the toroidal coil unit /J taken along the 2-θ plane in the coordinate system of FIG. 1, and FIG. 9 is an overall perspective view of the toroidal coil unit 12 of FIG. Components that are the same or corresponding to those in the figures or FIG.

On the inner surface of the toroidal coil alone, on the side of the center axis of the toroidal coil, a slit g extending in the direction of the center axis is formed to serve as an electrically insulating part.

Surin) J was provided on the central axis side of the toroidal coil by Poloidarco, Il 3. This is because the rate of change of the magnetic field in the central axis direction is large due to the magnetic field, and a large eddy current is induced compared to other parts. Also, the reason why Slin) ff is placed on the inner surface of the toroidal coil unit 12 is because centripetal force and hoop force act on the toroidal coil unit l, and when a slit is provided on the outer side of the toroidal coil unit lλ,
This is because Can 7 becomes weaker by degrees Celsius against electromagnetic force. Furthermore, if the slit 8 is formed on the side surface of the single toroidal coil lλ, the structure becomes weak against the rolling force fMj.

In the voloidal coil of the nuclear fusion device configured as described above, the voloidal coil 3. Q. When a magnetic field due to the plasma current is generated in the can 77' and an eddy current is generated in the can 7 as the magnetic field changes over time, the eddy current is generated by the slit t forming an electrically insulating part as shown in Fig. 9. arrow A
The current path is effectively lengthened by being detoured as shown in
At the same time, the eddy current loss is reduced and the eddy 1. The electromagnetic force due to the flow becomes smaller.

In addition, in the above example, the slit is linear.
However, if you can't remove it like that because of the 44 construction, 5. .

It may have a curved shape as shown in FIG. 1, or it may have a broken gland shape as shown in FIG. This is because they also increase the effective resistance to eddy currents.

Further, for the same reason, it is not necessary to completely electrically insulate the sulin) ff, and the can 7 may be connected with a thinner thickness. For example, by forming a sulin) ff with a U-shaped cross section in the can 7 as shown in Fig. 7, the cross-sectional area of the eddy current flow shown by arrow B becomes smaller, and the effective resistance increases. . Note that t is a heat insulating material that is used to protect the conductor 6 made of a superconducting conductor from heat generation due to eddy currents in the vicinity of f. This slit t may have a bellows shape.

Furthermore, since the electromagnetic force on the inner surface of the toroidal coil unit 12 is weaker than that of the outer surface, the slits tt of the first to third embodiments described above may be provided on the entire inner surface of the toroidal coil unit 12.

〔Effect of the invention〕

As explained above, the simple structure of providing a slit on the inner surface of the toroidal coil of the present invention to effectively increase resistance to eddy current and current can reduce eddy current loss by 1! This has the effect of reducing magnetic force.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the main parts of a conventional nuclear fusion device, and Figure 2 is a cross-sectional view of the main parts of a conventional nuclear fusion device.
3 is a sectional view showing the first embodiment of the toroidal coil of the present invention, and FIG. 3 is a sectional view of the toroidal coil of FIG. FIG. 3 is a perspective view of a single toroidal coil showing a third embodiment of this invention; FIG. 6 is a perspective view of a toroidal coil showing a third embodiment of this invention; FIG. 1 is a sectional view of a single toroidal coil showing a first embodiment of the invention. Ko, lkoe, toroidal coil alone 1.7, 4 I... voloidal coil, j*, plasma, 6... conductor, Rii...
Can, f-slit. In each figure, the same reference numerals indicate the same or corresponding parts. Coin 1 figure, 2 figures, 3 figures, 4 figures, 5 figures. Flame 6

Claims (1)

[Claims] (1) In a toroidal coil for a nuclear fusion device in which a single toroidal coil consisting of a conductor through which current flows and a can supporting the conductor is arranged radially,
(c) A nuclear fusion device characterized in that a slit is provided on the inner surface of the single toroidal coil to increase effective resistance to eddy current. The toroidal coil reel of the fusion device described in item 1.