JPS6155071B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a torus-type nuclear fusion device, and more particularly to a torus-type nuclear fusion device in which the toroidal coil is a superconducting toroidal coil formed of a superconductor.

In general, a torus-type fusion device has several or dozens of toroidal coil units arranged around the circumference of a torus-shaped vacuum vessel, and the magnetic field generated by the toroidal coils and the magnetic field generated by the poloidal coils described later. Therefore, plasma is confined in a vacuum container and energy is obtained through nuclear fusion.

In recent years, as nuclear fusion devices have become larger and more practical, strong and efficient toroidal coils have been required, and superconductors have been used instead of conventional copper conductors. It has become like that.

FIG. 1 and FIG. 2 schematically show a torus-type nuclear fusion device using a toroidal coil made of a superconductor.

In the figure, a toroidal vacuum vessel 1 that houses an internal plasma (not shown) has a plurality of vacuum vessels (not shown) made of a superconductor and housed in a cryogenic vessel filled with a cryogen such as liquid helium. Superconducting toroidal coils 2 surround it and are arranged at predetermined intervals in the circumferential direction of the torus, and furthermore, poloidal coils 4 to 6 of the current transformer and current transformer core 3 are provided on the outside thereof. Among the above poloidal coils, 4 in particular is a primary coil of a current transformer. These poloidal coils 4 to 6 mainly perform ionization, heating, and control of plasma, and are mainly excited by changing current.

In the illustrated torus-type fusion device, if the poloidal coil 4, which is the primary coil of the current transformer, is excited at a constant current rate of change, an electric field is generated in the direction of the arrow in FIG. Some kind of induced current flows. In particular, when the superconducting toroidal coil 2 is used, the cryostat surrounding the superconducting toroidal coil 2 forms a conductive circuit, so that an induced current flows in this portion and generates a Joule loss. The occurrence of this Joule loss results in an extremely large heat load on the cooling system (usually a helium refrigerator or helium liquefier) of the superconducting toroidal coil 2, and it not only causes a simple heat loss but also threatens the existence of the cooling system. In some cases.

In addition, coil units made of superconductors are housed in a cryogenic container filled with a cryogen such as liquid helium, and wedge-shaped spacers are installed between the coil units housed in a common insulated vacuum container. For example, Japanese Unexamined Patent Publication No. 145795/1984 proposes a system in which the electromagnetic forces acting between the coil units are mutually supported by the wedge action of a spacer. However, the spacer shown in JP-A-50-145795 is mechanically superior because it supports electromagnetic force, but the induced current as described above is No consideration had been given to what would happen if the water flowed.

The present invention has been made in view of the above-mentioned points, and its purpose is to prevent the generation of induced current in a cryostat in which a plurality of coil units made of superconductors are housed independently. Thereby, it is an object of the present invention to provide a torus-type nuclear fusion device that can minimize heat loss due to generation of Joule heat.

The present invention surrounds a torus-shaped vacuum vessel in which plasma is housed, and a plurality of superconducting toroidal coil units arranged at predetermined intervals in the direction of the torus are placed between low-temperature layers in which each unit is housed independently. The intended purpose is achieved by interposing an electrically insulating layer made of fiber-reinforced plastic, and a composite of these and a metal material.

Hereinafter, the present invention will be explained based on the drawings and examples.

FIG. 3 shows an embodiment of the present invention. Also in this embodiment shown in the figure, a torus-shaped vacuum vessel 1 containing plasma (not shown) is surrounded by a plurality of superconducting toroidal coil units 7 arranged at predetermined intervals in the torus direction. Each superconducting toroidal coil unit 7
are respectively housed in cryogenic chambers 8, and an electrically insulating layer 10 selected from plastic, fiber-reinforced plastic, and a composite of these materials and metal materials is interposed between each cryogenic chamber 8. There is. Further, all of these are housed in a common heat insulating tank 9 to constitute a torus type nuclear fusion device.

By having the configuration of this embodiment as described above,
A plurality of superconducting toroidal coil units 7 are housed in independent low temperature chambers 8 to subdivide the electric circuit, and furthermore, between these low temperature layers 8 are made of plastic, fiber reinforced plastic, and a combination of these materials and metal materials. Since it is insulated by the electrical insulating layer 10 selected from the composite, only a small amount of joule loss occurs in the subdivided low temperature layer 8 even if an induced current flows, and heat loss is also minimized. This has the effect of reducing the influence on the cooling system of the superconducting toroidal coil unit 7.

Next, FIG. 4 shows another embodiment of the present invention. Third
The difference from the embodiment shown in the figure is that a connecting pipe 11 made of a high-resistance structure such as a thin bellows is provided for common passage of refrigerant between the independently provided low temperature chambers 8.

By providing such a connecting pipe 11, the same effects as in the above-mentioned embodiment can be obtained, as well as forced cooling of the superconducting toroidal coil unit 7, setting of the common liquid level of the common tank of the low temperature chamber 7, etc. Another advantage is that it can be carried out conveniently.

According to the toroidal fusion device of the present invention as described above, a plurality of superconducting toroidal coil units surrounding a toroidal vacuum vessel in which plasma is housed and arranged at predetermined intervals in the direction of the torus are provided. , an electrically insulating layer made of plastic, fiber-reinforced plastic, or a composite of these and metal materials is interposed between each independently housed low-temperature layer, so each low-temperature layer is insulated by the electrically insulating layer. Therefore, even if an induced current is generated, heat loss due to the generation of Joule heat can be minimized, and this is very effective when used in this type of torus-type fusion device.

[Brief explanation of the drawing]

Fig. 1 is a horizontal sectional view showing a conventional torus-type fusion device, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 is a torus-type fusion device showing an embodiment of the present invention. FIG. 4 is a partial sectional view showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Vacuum container, 2... Superconducting toroidal coil unit, 8... Low temperature chamber, 9... Heat insulation tank, 10... Electric insulation layer, 11... Connecting pipe.

Claims (1)

[Scope of Claims] 1 A plurality of superconducting toroidal coil units surrounding a toroidal vacuum vessel in which plasma is housed and arranged at predetermined intervals in the direction of the torus are placed in independent low-temperature layers. In a torus-type nuclear fusion device in which each of these low-temperature layers is housed within a common heat insulating layer, an electrical conductor made of plastic, fiber-reinforced plastic, and a composite of these and metal materials is placed between the low-temperature layers. A torus-type nuclear fusion device characterized by an insulating layer. 2. The torus-type nuclear fusion device according to claim 1, further comprising a connecting pipe for commonly passing a refrigerant between the independently provided low-temperature layers.