JPS61207984A - Tokamak type 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 the Invention] The present invention relates to a tokamak-type nuclear fusion device in which the arrangement of poloidal coils in a plasma vacuum vessel is improved.

[Technical background of the invention and its problems]

The operating principle of a tokamak-type fusion device is that a donut-shaped vacuum container is placed around an iron or air core, and toroidal coils are arranged along this to create a toroidal magnetic field.
Plasma is generated by electric current generated by an electric field induced along a torus through an iron core according to the principle of a transformer.

In order to confine a ring-shaped torus plasma in a torus-shaped vacuum vessel, toroidal coils are arranged outside the vacuum vessel in the direction of the torus to create a toroidal magnetic field along the torus. A poloidal coil that generates a poloidal magnetic field that applies a perpendicular magnetic field is arranged, and the plasma is balanced within the vacuum vessel by the lines of magnetic force that are synthesized by the toroidal magnetic field and the poloidal coil magnetic field.

Therefore, the optimal placement location for the poloidal coil is a horizontal line along the center of the cross-section of the torus plasma, but this location usually has a space for pulling out the blanket or limiter plate, and also a space for high-frequency heating of the plasma. A waveguide is installed. Therefore, in conventional tokamak-type nuclear fusion devices, the poloidal coil is placed at a position away from the optimal position where it does not interfere with the extraction of the blanket, etc., at the expense of the effect of the poloidal magnetic field.

[Purpose of the invention]

An object of the present invention is to provide a tokamak-type nuclear fusion device in which the poloidal coil is arranged in the optimum position as possible, and in which the blanket, limiter plate, etc. can be easily replaced.

[Summary of the invention]

The tokamak-type nuclear fusion device according to the present invention is constructed by housing an outer poloidal coil provided outside the bell jar structure in an independent cryostad, and this outer poloidal coil is placed in a pull-out space such as a blanket, which is conventionally called a prohibited area. It is characterized by being placed close to the position where the poloidal magnetic field for the torus plasma is most effectively generated.

[Embodiments of the invention]

The present invention will be described below with reference to embodiments shown in the drawings. The plasma vacuum vessel 2 of the tokamak-type nuclear fusion device 1 according to the present invention is made into a torus shape that confines plasma 3 therein and maintains a high vacuum.

A blanket 4 is integrally provided on the inner surface of the vacuum container 2 so as to surround the plasma 3.

The blanket 4 has a first wall on the front side, contains lithium as a tritium breeding material therein, and is provided with a coolant flow path for cooling the lithium.

The blanket 4 reacts high-energy neutrons emitted from the plasma 3 with lithium to generate tritium. The heat energy generated at this time is extracted to the outside by the coolant flowing through the coolant flow path.

Furthermore, a toroidal coil 5 provided in the toroidal direction of the vacuum container 2 and a poloidal coil 6 provided in the poloidal direction of the vacuum container 2 are provided around the vacuum container 2 . The poloidal coil 6 outside the toroidal coil 5 is arranged so as not to interfere with the blanket that is pulled out in the radial direction of the torus during overhaul.
Both the poloidal coil 6 and the toroidal coil 5 are placed in a common vacuum container, a bell jar structure 13.

A central support 7 is provided passing through the hollow portion of the vacuum container 2 from above and below. A current transformer coil 8 is wound around the central support 7, and is configured to cause a high current to flow through the current transformer coil 8 to Joule-heat the plasma 3 within the vacuum vessel 2.

Further, a shielding body 9 is provided around the outer periphery of the vacuum container 2 so as to surround it, and is configured to prevent radiation from leaking to the outside. This shield 9 has a thickness that allows a person to access it after a certain period of time after the furnace is shut down.

Furthermore, a secondary heating device is arranged around the vacuum container 2, and this secondary heating device receives high-frequency waves via a coupling system 10 such as a waveguide provided at multiple locations on the outer peripheral surface of the vacuum container 2. It is configured to perform heating and further heat the plasma or drive a plasma current. Also, vacuum container 2
A limiter plate 12 is placed near the vacuum exhaust port 11 of the
It is configured to neutralize the plasma, exhaust gas, and maintain a high vacuum.

In the present invention, in the tokamak type nuclear fusion device 1 configured as described above, an outer poloidal coil 6a is provided outside the poloidal coil 6 provided inside the bell jar structure 13.
, 6b are provided outside the bell jar structure 13. Moreover, these outer poloidal coils 6a, 6b are
As shown in the figure, it is housed in an independent taliostat 14, and is further placed as close as possible above and below the optimal placement line x-X connecting the cross-sectional centers of the torus plasma 3, and a heat insulating support 15 It is characterized by being attached via. The optimum arrangement of the poloidal coils 6a and 6b is on the line X-x, but since the coupling line 10 of the heating device is usually placed on this line as shown in the figure, it should be kept away from these interferences. The position is set close to the optimal placement line xx under certain conditions. This arrangement of the outer poloidal coils 6a, 6b generates an effective poloidal magnetic field for the torus plasma 3.

In the tokamak-type nuclear fusion device 1 according to the present invention configured as described above, when the blanket 4 is to be pulled out for disassembly and repair, the outer poloidal coils 6a and 6b are removed. Once the coupling system 10 is removed, the upper and lower outer poloidal coils 6a, 6b can be pulled upwardly along the upper side of the bell jar structure 13 and removed.

The removal of the outer poloidal coils 6a and 6b can be done after the coils have been heated up or while they are being cooled.If done while the coils are being cooled, the process of heating up and cooling the coils can be omitted and the process of disassembly is possible. Furnace downtime for repairs is reduced. Outer poloidal coils 6a, 6b
After removing the bell jar structure 13, a pull-out opening 16 is made in the side surface of the bell jar structure 13, and the separate parts of the blanket 4 and the limiter plate 12 can be pulled out from there.

In addition, the independent cryostads 14 of the outer poloidal coils 6a and 6b are connected to coupling wires 1 of heating devices, etc., as shown in the figure.
In order to avoid interference with the coils 6a and 6b, the independent cryostad 1 of both coils 6a and 6b is connected to the
4a and 14b are connected by a support 14c, and both coils 6a and 6b are supported as one body. Furthermore, apart from the blanket 4, the limiter plate 12 is replaced more frequently than the blanket 4, but the outer poloidal coil 6a
, 6b, the structure allows the coil to be pulled out from between the poloidal coils 6a, 6b and the toroidal coil 8 without moving.

〔Effect of the invention〕

As described above, according to the present invention, an outer poloidal coil provided outside the bell jar structure is housed in an independent cryostad in addition to the poloidal coil provided inside the bell jar structure and on the outer periphery of the vacuum vessel. By placing the poloidal coil close to the position where the poloidal magnetic field for the torus plasma is most effectively generated within the extraction space such as a blanket, which is traditionally called the prohibited area, the outer poloidal coil is brought closer to the optimum position. This has the advantage that a poloidal magnetic field is effectively generated, plasma equilibrium is facilitated, and the poloidal coil power supply capacity is reduced, and blankets etc. can be easily replaced. play.

[Brief explanation of drawings]

No. trsl is a sectional view showing an embodiment of a tokamak type nuclear fusion device according to the present invention.

Claims (3)

[Claims] (1) In addition to the inner poloidal coil located inside the bell jar structure and provided around the vacuum vessel, an outer poloidal coil provided on the outer periphery of the bell jar structure is housed in a cryostad, and this outer poloidal coil is pulled out from a blanket, etc. A tokamak-type nuclear fusion device characterized by being located in space close to a position where a poloidal magnetic field for torus plasma is most effectively generated. (2) The tokamak type nuclear fusion device according to claim 1, wherein the outer poloidal coil is two poloidal coils disposed vertically sandwiching the coupling system of the heating device to the vacuum vessel. (3) The tokamak-type nuclear fusion device according to claim 2, characterized in that each cryostad of the two poloidal coils is connected by a support.