JPS5952784A - 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] [Technical field of invention] The present invention relates to a nuclear fusion device.

[Technical background of the invention]

A conventional example will be explained with reference to FIGS. 1 to 3. FIG. 1 is a schematic diagram of a nuclear fusion device.

In the figure, 1 indicates a vacuum container. This vacuum vessel 1 has a toroidal shape and contains a plasma 2 fueled with deuterium (D) and tritium (T) inside to maintain a high vacuum. A blanket 3 is provided inside the vacuum container 1 so as to surround the plasma 2. This blanket 3 contains a tritium breeding material made of ceramic such as Li20.

Neutrons of 14 MeV are generated from the plasma 2, and these neutrons multiply tritium and generate neutron heat within the blanket 3. The cooling material is then taken out to the outside by a coolant flowing through a cooling pipe (not shown) disposed inside the hot blanket 3. A shield 4 is provided between this blanket 3 and the admission container 1.

A toroidal coil 5 is provided on the outer periphery of the vacuum vessel 1, and a voloigle coil 6 is further provided on the outer periphery of the toroidal coil 5. This poloidal coil 6 is provided as close as possible to the plasma 2 side. This is because the aspect ratio (R/a, R:
This is to reduce the plasma major radius (a: plasma minor radius), improve the coupling between the poloidal coil 6 and the plasma 2, and reduce the power supply capacity. The plasma 2 is contained by the toroidal coil 5, and the poloidal coil 6 controls the rise and fall of the plasma 2, as well as its position and shape. Further, both the toroidal coil 5 and the poloidal coil 6 are constructed of superconducting coils. In the figure, 7 indicates a bell jar, and 8 indicates an access tunnel for approaching the shield 4. In general, the shield 4, the blanket 3, and the vacuum vessel 1
etc., must have a sufficiently higher one-turn resistance in the torus direction than the plasma 2.

This is because when the poloidal coil 6 is used to control the startup, shutdown, position, and shape of the plasma 2, the production current of the poloidal coil 6 is induced in the shield 4, the blanket 3, and the vacuum vessel 1. This is to prevent this. Therefore, as shown in FIG. 3, high resistance bellows 9 and 10 are provided on the shield 4 and the vacuum vessel 1, respectively. The high-resistance bellows 9 and 10 allow the shield 4 and the vacuum vessel 1 to have a high one-turn resistance.

The shield 4 and the blanket 3 each have an insulating material 11 made of ceramic or the like in the divided portions, and this insulating material 11 also increases the one-turn resistance.

[Problems with background technology]

According to the above configuration, by providing the bellows 9 and 10 in the shielding body 4 and the vacuum vessel 1, the shielding thickness in those parts is thin, and the specific resistance of the superconducting conductor of the redroidal coil 5 exceeds the service limit value in a short period of time. In other words, there is a risk that the resistance value of the stabilizing steel will exceed its limit, and in order to recover from this, annealing is required for a short period of time, which may cause a decrease in the operating rate of the device.

[Purpose of the invention]

The purpose of the present invention is to prevent the situation in which the specific resistance of the superconducting conductor of the toroidal coil exceeds the usage limit value in a short period of time, and thereby improve the reliability of the device by improving its operating rate. The objective is to provide a high-performance nuclear fusion device.

[Summary of the invention]

A nuclear fusion device according to the present invention includes a vacuum vessel having a toroidal shape and having a bellows to contain a plasma therein, a blanket provided inside the vacuum vessel so as to surround the plasma and containing a breeding material, the vacuum vessel and the blanket. a toroidal coil provided on the outer periphery of the vacuum vessel; and an auxiliary shield provided on either the inside or outside of the bellows provided on the shield. The configuration includes a body.

In other words, by providing an auxiliary shield on at least one of the inside and outside of the bellows provided on the shield, the shielding thickness at the bellows portion is ensured.

Therefore, even if it is placed in the bellows part, the shielding thickness can be ensured, so it is possible to prevent the situation where the specific resistance of the superconducting conductor of the toroidal coil exceeds the usage limit value in a short period of time. This is extremely effective in improving operating rates.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 4 to 6.

Figure 4 is a schematic diagram of the nuclear fusion device.
indicates a vacuum container. This vacuum vessel 10) has a toroidal shape and contains deuterium (D), t;- and tritium (T>
A high vacuum is maintained by confining the plasma 102 fueled by The plasma 10 is inside this vacuum container lθ).
A blanket 103 is provided to surround 2.

A tritium breeding material made of ceramic, such as L120, is housed within this Planckeat 103.

Neutrons of 14 MeV are generated from the plasma 102, and these neutrons multiply tritium and cause neutron heat generation within the blanket 103.

The heat is then extracted to the outside by a coolant flowing through a cooling pipe (not shown) disposed within the blanket 103. A shield 104 is provided between this blanket 03 and the vacuum container 101. A toroidal coil 105 is provided on the outer periphery of the vacuum vessel 101, and a poloidal coil 106 is provided on the outer periphery of the vacuum vessel 101.
is provided. The poloidal coil 106 is provided as close as possible to the plasma 102 side.

This is determined by the aspect ratio (R/a) in order to improve the performance of the plasma 102.

This is to reduce the Rnear'' lasma major radius (a, plasma minor radius), improve the coupling between the poloidal coil 106 and the plasma 102, and reduce the power supply capacity. The configuration is such that the poloidal coil 106 controls the start-up, fall, position, and shape of the plasma 102.The toroidal coil 105 and the poloidal coil 106 are both constructed of superconducting coils.In the figure, 107 is a bell jar. and 108 indicate access tunnels for approaching the shield 104, respectively.

High resistance bellows 109 and 110 are provided on the shield 104 and the vacuum vessel 101, respectively. The high resistance bellows 109 and 110 allow the shielding body to
4 and the vacuum container 101 have a structure that can have a high one-turn resistance. -! ! The shield 104 and the blanket 103 each have an insulating material 11 made of ceramic or the like in the divided portions, and the insulating material 111 increases the one-turn resistance.

Auxiliary shields 1 are provided inside and outside the bellows 109.
12 and 113 are provided respectively, and the auxiliary shield 112 is? The edge of the shield θ4KJp3 is fixed to the side 116.

Still this auxiliary shield 112 and 113 and bellows 10
Insulating coatings 114 and 115 are provided between them and 9, respectively. The insulating coatings 114 and 115 are made of ceramic-coated material, lIJ imide, or the like. The auxiliary shields 112 and 113 are installed in multiple sections in the poloidal direction, and steps are provided at their joints to prevent the neutrons generated from the plasma 102 from being exposed.

According to the above configuration, a sufficient shielding thickness can be secured in the bellows 109 without impairing the conventional configuration, and the specific resistance of the superconducting conductor of the toroidal coil 105, which was a concern in the past, can be reduced within a short period of time. It is possible to prevent a situation in which the usage limit value is exceeded, and there is no need for annealing, and the operating rate of the device can be greatly improved. Further, the bellows 109 is made of a thin plate and has a long length in order to obtain a high one-turn resistance. For this reason, there is a concern about the strength in a situation where the outside is 1 atm and the inside is a vacuum, but the auxiliary shields 112, 11
3, the bellows 109 can be supported and the displacement of the bellows 109 can be prevented. a blanket provided to surround the plasma and contain a breeding material; a shield provided between the vacuum container and the blanket and having a bellows; a toroidal coil provided around the outer periphery of the vacuum container; This configuration includes an auxiliary shield provided on either the inner side or the outer side of the provided bellows.

In other words, by providing an auxiliary shield on at least one of the inside and outside of the bellows provided on the shield, the structure is designed to ensure the shielding thickness at the bellows portion.

Therefore, it is possible to secure the shielding thickness even in the bellows part, which prevents the situation in which the specific resistance of the superconducting conductor of the toroidal coil exceeds the usage limit value in a short period of time, making it possible to prevent the operation of the device. The effects are great, such as being able to improve the rate.

[Brief explanation of drawings]

Figures 1 to 3 are diagrams showing conventional examples. Figure 1 is a schematic configuration diagram of a nuclear fusion device, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, and Figure 3 is a part of Figure 2. Enlarged views, @Figures 4 to 6 are diagrams showing one embodiment of the present invention, Figure 4 is a schematic configuration diagram of a nuclear fusion device, Figure 5 is a sectional view taken along the line ■-■ of Figure 4, and Figure 6 is a partially enlarged view of No. 5 A. 101... Vacuum container, 102... Plasma, 103
...blanket, 104...shielding body, 105...
- Toroidal coil, 109... Bellows, 112° 113... Auxiliary shield. Figure 1 Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) A vacuum vessel having a toroidal shape and having a bellows to contain plasma therein, a blanket provided inside the vacuum vessel so as to surround the plasma and containing a breeding material, and a space between the vacuum vessel and the blanket. a toroidal coil provided on the outer periphery of the vacuum vessel; and an auxiliary shield provided on either the inside or outside of the bellows provided on the shield. A nuclear fusion device characterized by: (2) The nuclear fusion device according to claim 1, wherein the auxiliary shield is provided inside and outside the bellows with an insulating material interposed therebetween.