JPH026034B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a protection device for a coil in a vacuum container,
In particular, the present invention relates to a protection device for a coil in a vacuum vessel suitable for a diverter coil or the like installed for the purpose of reducing impurities inside a vacuum vessel for a nuclear fusion device.

Generally, a nuclear fusion device, as shown in FIGS. 1 and 2, includes a donut-shaped vacuum container 2 that houses plasma 1 that causes nuclear fusion, and this vacuum container 2.
A plurality of toroidal coils 3 are arranged at appropriate intervals in the circumferential direction of the torus in order to generate a strong magnetic field in a toroidal direction at the plasma position and to stably confine the plasma 1. In particular, the toroidal coil 3 is arranged along the inner diameter side, and is generally composed of a plurality of poloidal coils 4 interlinked with the toroidal coil 3.
The centripetal force is supported by the center support 5, which is further held by upper and lower frames 6, 7, and support 8.
On the other hand, the vacuum vessel 2 is supported by a vacuum vessel support arm 9, and the toroidal coil 3 is supported by a toroidal coil support 10. Further, inside the vacuum vessel 2, a vacuum vessel coil 11 such as a diverter coil is provided for the purpose of reducing impurities in the vacuum vessel 2. A magnetic field is created to remove impurities in plasma 1 and maintain high temperature plasma 1 with little loss.

Normally, the coil 11 in the vacuum container is connected to the protective tube 12.
covered by. The protective tube 12 is configured by alternately arranging thick-walled portions and bellows portions, and supports the protective tube 12 by fixing the thick-walled portions to the inner wall of the vacuum container 2 via a support member 13. The protective tube bellows not only increases the electrical resistance of the protective tube 12, but also protects the vacuum vessel 2 and the protective tube 12 during plasma operation.
This absorbs the expansion difference caused by the large temperature difference that occurs between the two. Note that the outside of the protection tube 12 is in a vacuum, and the inside is in the atmosphere.

By the way, the protection tube 12 increases the electrical resistance,
The bellows portion should be as thin and long as possible in order to absorb the difference in expansion well. However, in the conventional protection device for a coil in a vacuum vessel having such a structure, the thick part of the protection tube 12 itself is directly supported on the inner wall of the vacuum vessel 2, but the bellows part is supported indirectly through the thick part. It is only supported by Therefore, the rise of plasma current,
Or when an electromagnetic force is generated in the protective tube 12 in the radial direction or in the vertical direction due to an induced current caused by current changes such as during other current fluctuations,
Since the bellows portion of the protective tube has low rigidity, it tends to undergo large displacement, resulting in a large amount of stress.
In order to withstand this, it is not possible to increase the electrical resistance or to make the protective tube bellows part thinner or longer in order to better absorb the difference in expansion.

Therefore, the conventional configuration has the drawback that the electric resistance value cannot be set high enough, which adversely affects the rise and containment of plasma.

The present invention has been made in view of the above-mentioned points, and its purpose is to suppress the displacement of the bellows portion of the protective tube, which has low rigidity, and to maintain a sufficiently high electrical resistance value, thereby suppressing the plasma. To provide a protection device for a coil in a vacuum container that does not adversely affect startup and closure.

The present invention is arranged concentrically with the vacuum vessel along the inner wall surface of the vacuum vessel, the outer periphery of which contains plasma and is surrounded by a plurality of toroidal coils, in order to remove impurities from the inside. A bellows portion of a protective tube, which is formed by alternately arranging thick-walled portions and bellows portions, is supported and fixed to the coil within the vacuum container at a predetermined interval radially. The intended purpose is achieved by supporting the protective tube bellows portion to the coil in the vacuum container through a plurality of supporting members so as to suppress displacement.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings. Incidentally, the same reference numerals are used for the same parts as in the past.

FIG. 3 shows an embodiment of the vacuum container coil protection device of the present invention, and is a cross-sectional perspective view of the interior of the vacuum container 2 housing the vacuum container coil 11.

In the figure, a vacuum container coil 11 such as a diverter coil housed in a vacuum container 2 is
The coil 11 in the vacuum container is usually covered with a protective tube 12 having thick walled portions 14 and bellows portions 15 arranged alternately. 12 are supported and fixed to the inner wall of the vacuum container 2 by protective tube supporting members 17, respectively. In this embodiment, the protection tube 12
The bellows portion 15 is supported on the vacuum vessel coil 11 by a plurality of stoppers 18 radially attached to the vacuum vessel coil 11 at predetermined intervals. When supporting the bellows part 15 of the protection tube 12 to the coil 11 in the vacuum vessel with each stopper 18, an intermediate ring 19 is provided in the middle of the bellows part 15, and this intermediate ring 19 is inserted into the vacuum vessel through each stopper 18. It is supported by a coil 11 to suppress displacement of the bellows portion 15 in the radial direction or in the vertical direction.

By having the configuration of this embodiment as described above,
Even if a radial or vertical electromagnetic force is generated in the protection tube 12 due to an induced current during the rise of the plasma current or other current fluctuations, the bellows portion 15 of the protection tube 12 can be moved through the stopper 18 into the vacuum chamber. Since it is supported by the coil 11, displacement occurring in the bellows portion 15 can be suppressed, and stress generation in the bellows portion 15 can also be suppressed. That is, when a change occurs in the current in the coil 11 in the vacuum container, the coil 11 in the vacuum container and the bellows portion 15
The electromagnetic force acting in the opposite direction is canceled out by the bellows portion 15 being supported by the vacuum container coil 11 via the stopper 18 attached to the vacuum container coil 11. Displacement occurring in the bellows portion 15 is suppressed.

Therefore, the strength of the protection tube 12 is increased, and the bellows portion 15 can be made thinner or longer, so that the electrical resistance value of the protection tube 12 can be kept sufficiently high, and there is no negative effect on the rise and containment of plasma. It is possible to obtain a highly reliable product that generates and maintains good plasma without causing any adverse effects. still,
Normally, a gap is maintained between the stopper 18 and the intermediate ring 19, so even if there is a relative displacement between the coil 11 in the vacuum container and the protective tube 12 due to the difference in thermal expansion, this gap can absorb it. , is more effective.

According to the above-described protection device for a coil in a vacuum vessel of the present invention, plasma is housed inside, and the outer periphery is surrounded by a plurality of toroidal coils. It covers the periphery of a coil in a vacuum container that is arranged in a shape and is provided to remove impurities inside the container,
The bellows portion of the protective tube, which is formed by alternately arranging thick-walled portions and bellows portions, is connected to the coil in the vacuum container via a plurality of supporting members that are radially supported and fixed to the coil in the vacuum container at predetermined intervals. Since the bellows part of the protection tube is supported so as to suppress displacement, the electromagnetic force in the opposite direction acting on the coil in the vacuum vessel and the bellows part causes the bellows part to be supported by the coil in the vacuum vessel via the support member. Since mutual forces cancel each other out, the stress in the bellows part is suppressed, and the strength of the protection tube increases. This allows the bellows part to be made thinner or longer, and the electrical resistance value of the protection tube can be made sufficiently high. There is no negative effect on the rise and containment of plasma, so
This type of device is very effective when used as a protection device for a coil inside a vacuum vessel.

[Brief explanation of drawings]

Fig. 1 is a schematic front view showing an example of a nuclear fusion device in which a protection device for a coil in a vacuum vessel is adopted, Fig. 2 is a partially sectional plan view thereof, and Fig. 3 is a vacuum vessel of the present invention. FIG. 2 is a cross-sectional perspective view of the inside of a vacuum container showing an embodiment of an inner coil protection device. DESCRIPTION OF SYMBOLS 1... Bellows, 2... Vacuum container, 3... Toroidal coil, 4... Poloidal coil, 11... Coil in vacuum container, 12... Protection tube, 14... Protection tube thick part,
15... Protection tube bellows part, 16... Coil support material,
17... Protection tube support material, 18... Stopper, 19...
intermediate ring.

Claims (1)

[Scope of Claims] 1. A vacuum vessel containing plasma and whose outer periphery is surrounded by a plurality of toroidal coils, and a vacuum vessel arranged concentrically with the vacuum vessel along the inner wall surface of the vacuum vessel. A coil for removing impurities inside the container, a protection tube formed by alternately arranging thick-walled parts and bellows parts surrounding the coil inside the vacuum container, and a protection tube that is connected to the coil through the thick-walled part. and a protection tube support member supported and fixed to the inner wall of the vacuum container, wherein a bellows portion of the protection tube is supported and fixed to the coil in the vacuum container at a predetermined interval radially. 1. A protection device for a coil in a vacuum vessel, characterized in that a bellows portion of a protection tube is supported on the coil in a vacuum vessel via a plurality of supporting members arranged in a manner such that displacement of a bellows portion of a protective tube is suppressed. 2. The vacuum container according to claim 1, wherein an intermediate ring is provided in the middle of the bellows portion of the protection tube, and the intermediate ring is supported by the support member so as to suppress displacement of the bellows portion. Inner coil protector. 3. The support member is a stopper that is supported and fixed radially to the coil in the vacuum container at a predetermined interval, and the stopper supports the bellows portion of the protective tube to the coil in the vacuum container so as to suppress its displacement. A protection device for a coil in a vacuum container according to claim 1 or 2, characterized in that: