JPS6222117B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nuclear fusion device, and more particularly to a nuclear fusion device in which a poloidal magnetic field coil arranged along a donut-shaped vacuum container is supported by the vacuum container.

A nuclear fusion device uses a magnetic field to confine high-temperature plasma inside a vacuum container away from the container wall. In a torus-type fusion device, a toroidal magnetic field coil that generates a high magnetic field to create this magnetic field wall, and It is equipped with a poloidal magnetic field coil for stable maintenance of high-temperature plasma and position control. A nuclear fusion device equipped with this toroidal and poloidal magnetic field coil is schematically shown in FIGS. 1 and 2.

In the figure, reference numeral 2 denotes a vacuum vessel formed into a substantially doughnut-like shape by alternately arranging thick-walled parts 3 and bellows parts 4, and a plasma 1 is confined inside the vacuum vessel. A plurality of toroidal magnetic field coils 5 surround the vacuum vessel 2 and are arranged at predetermined intervals in the circumferential direction of the torus. On the other hand, the poloidal magnetic field coil 6 is connected to the vacuum vessel 2 and the toroidal magnetic field coil 5.
It is arranged along the vacuum vessel 2 between.
Note that 8 is a vacuum evacuation device for evacuating the inside of the vacuum container 2, and 9 is an upper and lower pedestal that supports the toroidal magnetic field coil 5 via a support.

In the nuclear fusion device configured in this way, the poloidal magnetic field coil 6 must apply a magnetic field to the plasma 1 inside the vacuum vessel 2, so it is better to install it at the smallest possible distance from the vacuum vessel 2. This is advantageous in terms of coupling with the plasma 1, power capacity of the poloidal magnetic field coil 6, and saving limited space. For this reason, the poloidal magnetic field coil 6 is usually attached directly to the outer wall of the vacuum vessel 2. That is, as the details of the mounting structure are shown in FIG. 5, the poloidal magnetic field coil 6 is fixedly supported on the vacuum vessel 2 by a support member 12 at a predetermined position in the circumferential direction of the torus.

However, with this conventional configuration, the temperature of the vacuum vessel 2 increases or decreases, and as shown in FIG. or if the poloidal magnetic field coil 6 itself is deformed or displaced due to temperature rise or fall, forced displacement is applied to the poloidal magnetic field coil 6 due to these relative displacements, and at this time, the poloidal magnetic field coil 6 6. There is a possibility that the stress and strain generated in the case may become excessive. Furthermore, since electromagnetic force acts on the poloidal magnetic field coil 6, the support member 12 is necessary to support this electromagnetic force. If it was supported fixedly, there would be problems in terms of strength. Furthermore, Japanese Patent Application Laid-open No. 50316/1983 discloses a magnetic field coil support device in which rollers that slide in the radial direction are provided on the upper and lower sides of a magnetic field coil, and the rollers are elastically supported. In other words, in this example, the sliding structure prevents the generation of stress against the thermal forced displacement in the torus circumferential direction that the magnetic field coil receives, but the stress is is not supported, but is supported elastically against vertical forces.

However, in this example, although the vertical force of the magnetic field coil is supported by elastic support, the bending moment generated in the magnetic field coil remains unchanged with this support method, so elastic support is not effective in reducing the stress of the magnetic field coil. In order to reduce stress in the magnetic field coil due to thermally forced displacement, an expensive and complicated slide mechanism is essential.

The present invention has been made in view of the above points, and its purpose is to support the poloidal magnetic field coil with a simple structure without increasing stress or strain even when electromagnetic force and thermal displacement are applied to the poloidal magnetic field coil. The aim is to provide a nuclear fusion device that can

The present invention achieves the intended purpose by elastically supporting a poloidal magnetic field coil provided along the circumferential direction of the torus of a nearly donut-shaped vacuum container that houses plasma inside the vacuum container at a plurality of locations. This is how it was done.

The present invention will be explained below based on the illustrated embodiments. Incidentally, the same reference numerals are used for the same parts as in the past.

FIG. 7 shows an embodiment of the present invention. As shown in the figure, in this embodiment, a poloidal magnetic field coil 6 is arranged along the circumferential direction of the torus of the vacuum vessel 2.
, an elastic body 15 is formed at a predetermined location in the circumferential direction of the torus.
It is supported in the vacuum container 2 by a support member 12 via. The elastic body 15 is provided to cover the periphery of the poloidal magnetic field coil 6 at the support location, and the elastic body 15 is further covered with a U-shaped support member 12 to support the poloidal magnetic field coil 6 in the vacuum container 2. . The elastic body has an appropriate spring constant commensurate with the stiffness of the coil.

Usually, as shown in Figures 8 and 9, the electromagnetic force 16
When acts on the poloidal magnetic field coil 6,
The stress and strain generated in the poloidal magnetic field coil 6 are larger in the support structure using the elastic body 15 as shown in FIG. 9 than in the case of the fixed support structure 14 shown in FIG. 8. On the other hand, when forced displacement δ acts as shown in FIGS. 10 and 11, it is better to support the poloidal magnetic field coil 6 with an elastic body 15 as shown in FIG. In comparison, the stress and strain generated in the poloidal magnetic field coil 6 are smaller.

FIG. 12 shows these relationships. In other words, if we take the spring constant k of the elastic body 15 on the horizontal axis and the stress σ generated in the poloidal magnetic field coil 6 on the vertical axis, the relationship between k and σ is expressed by a curve 1 with respect to the electromagnetic force 16.
8. Curve 17 is obtained for forced displacement such as thermal displacement.

At this time, if the upper limit value of the stress of the poloidal magnetic field coil 6 is σ _nax , an appropriate spring constant k of the elastic body 15 can be determined by k _nio ≦k≦k _nax .

By having the configuration of this embodiment as described above,
Even if a forced displacement is applied to the poloidal magnetic field coil 6 when the temperature of the vacuum vessel 2 or the poloidal magnetic field coil 6 increases or decreases, the generated stress will be reduced because the poloidal magnetic field coil 6 is supported by the elastic body 15. The distortion will not increase,
Suitable support can be provided against forced displacement such as thermal displacement. In addition, the support member 1
2 can be supported and there are no particular problems.

According to the nuclear fusion device of the present invention described above, the poloidal magnetic field coil provided along the circumferential direction of the torus of the donut-shaped vacuum container is elastically supported at a plurality of locations on the vacuum container, so that the poloidal magnetic field is Even when electromagnetic force and thermal displacement are applied to the coil, it can be supported with a simple structure without increasing stress or strain, which is very effective for this type of device.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional plan view of a torus-type fusion device; Fig. 2 is an AA sectional view thereof;
Fig. 3 is a plan view of a vacuum vessel equipped with a poloidal magnetic field coil, Fig. 4 is a cross-sectional view taken along line BB, Fig. 5 is a cross-sectional view of the vacuum vessel showing the installation state of a conventional poloidal magnetic field coil, and Fig. 6 7 is a cross-sectional view of a vacuum container showing an embodiment of the poloidal magnetic field coil of the present invention, and FIGS. 8 and 9 are diagrams showing the state after the displacement. Fig. 8 shows the case of fixed support, Fig. 9 shows the case of elastic support, Fig. 10, and Fig.
Figure 1 shows the state in which the poloidal magnetic field coil is forcibly displaced, Figure 10 shows it when it is fixedly supported, and Figure 1 shows the state in which the poloidal magnetic field coil is forcibly displaced.
FIG. 1 is a diagram showing the case of elastic support, and FIG. 12 is a characteristic diagram showing the relationship between the spring constant of the elastic body and the stress generated in the poloidal magnetic field coil. DESCRIPTION OF SYMBOLS 1... Plasma, 2... Vacuum container, 5... Toroidal magnetic field coil, 6... Poloidal magnetic field coil, 12...
Supporting member, 15...Elastic body, 16...Electromagnetic force.

Claims (1)

[Scope of Claims] 1. A substantially donut-shaped vacuum container that stores plasma therein, a plurality of toroidal magnetic field coils that surround the vacuum container and are arranged at predetermined intervals in the circumferential direction of the torus, and A nuclear fusion device comprising a poloidal magnetic field coil provided along the circumferential direction of a torus of a container, wherein the poloidal magnetic field coil is elastically supported by the vacuum container at a plurality of locations. 2. A patent characterized in that the poloidal magnetic field coil is entirely covered with an elastic body at its support location, and the elastic body is covered with a U-shaped support member and supported in the vacuum container. A nuclear fusion device according to claim 1.