JPS5950952B2 - nuclear fusion device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nuclear fusion device, and more particularly to a toroidal fusion device that confines toroidal plasma using a magnetic field.

As shown in FIG. 1, the torus-shaped fusion device includes a toroidal vacuum vessel 2 that confines plasma 1 therein, a toroidal coil 3 that generates a magnetic field for plasma confinement, vertical magnetic field coils 51 and 52, and a vertical magnetic field unwinding coil 61.゜62
, and a horizontal magnetic field coil (not shown), the toroidal coil 3 is supported by a coil support 4, and the upper and lower ends of the coil support 4 are fixed to the base 7.

The vertical magnetic field coils 51 and 52 are connected to the base 7 of the plasma 1.
The vertical magnetic field coil 5 is arranged along the vacuum vessel 2 at vertically symmetrical positions with respect to the horizontal center parallel to the vertical axis, and generates a vertical magnetic field parallel to the torus center line of the plasma 1.
1.52 can form a magnetic field that confines the plasma 1 and change the major radius of the plasma 10.

That is, when a current flows through the toroidal plasma 1,
If the magnetic field generated by the vertical magnetic field coils 51 and 52 is strengthened in the same direction as the vertical magnetic field created by this current on the torus center line, the major radius of plasma 1 will increase, and if it is strengthened in the opposite direction, the major radius of plasma 1 will be decreased. Become.

On the other hand, a magnetic field parallel to the horizontal center of the plasma 1 and symmetrical with respect to the center line of the plasma (hereinafter referred to as a horizontal magnetic field) generates a force that moves the plasma 1 in the vertical direction.

If a fusion device is made completely symmetrical about its horizontal center, the horizontal magnetic field at the inner surface of the horizontal center will be zero, and the plasma will not move up or down.

However, in actual devices, some kind of horizontal magnetic field is generated due to manufacturing tolerances or external factors such as geomagnetism, which shifts the position of the plasma in the vertical direction.

Usually, the magnitude of this horizontal magnetic field is about one-tenth of the vertical magnetic field.

Next, the principles of vertical magnetic field coils and horizontal magnetic field coils will be explained.

FIG. 2 is a conceptual diagram showing the principle of generation of a rectangular magnetic field.

When currents in the same direction flow through a pair of upper and lower coils 81 and 82, a vertical magnetic field Bv parallel to the coil center axis is generated.

If the current flows in the opposite direction, the direction of the vertical magnetic field Bv will also be reversed.

FIG. 3 is a conceptual diagram showing the principle of horizontal magnetic field generation.

In this case, currents in opposite directions are passed through the upper and lower coils 91 and 92.

In the connection as shown in FIG. 3, a horizontal magnetic field BR directed outward from the coil center axis is generated.

If the current flows in the opposite direction, a horizontal magnetic field is generated from outside toward the center axis of the coil.

The above is the principle diagram of vertical magnetic field coils and horizontal magnetic field coils. In conventional nuclear fusion devices, a dedicated horizontal magnetic field coil is provided to cancel the horizontal magnetic field that is caused by the above-mentioned manufacturing tolerances and external factors such as geomagnetism. A coil was used to adjust the vertical position of the plasma.

However, this conventional method requires the installation of a new horizontal magnetic field coil and its power supply, making the device larger and more complex, which poses problems in terms of economy and reliability.

The present invention was made to eliminate such conventional drawbacks, and its purpose is to be able to adjust the vertical position of plasma without using a horizontal magnetic field coil,
Therefore, it is an object of the present invention to provide a nuclear fusion device that is simple in structure, reliable, and lasts for one year without increasing the size of the device.

The present invention is arranged vertically symmetrically with respect to a horizontal axis extending perpendicularly to the torus center axis of a torus-shaped vacuum container that confines plasma therein, and each of which is arranged along the vacuum container. The intended purpose is achieved by making the magnetomotive forces of the upper and lower vertical magnetic field coils, which generate vertical magnetic fields parallel to the lath central axis, different from each other.

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 4 is a circuit diagram of an array of vertical field coils embodying the invention.

In this example, independent power supplies 111 and 112 are connected to the upper and lower two coils 101 and 102 to flow currents of different values.

If the current flowing in the upper coil 101 is 1 + 2 and the current flowing in the lower coil 102 is 1l - I2, the current component 1 flowing in the same direction in the upper and lower coils 101 and 102 generates a vertical magnetic field, and the coil 101, A horizontal magnetic field is generated by the current components (2) flowing in opposite directions to each other.

That is, in the embodiment of FIG. 4, a pair of vertical magnetic field coils 101
, 102, an independent power supply 111,1 for each block.
By adding 12, a horizontal magnetic field can also be generated.

In this embodiment, a thyristor rectifier is used as the power source 111, 112, but the same effect can be achieved even if current is supplied from a capacitor, inductor, DC generator, etc.

FIG. 5 is a circuit diagram of another example implementing the present invention.

Resistor 1 is connected to one side 102 of the two upper and lower coils 101 and 102.
2 are connected in parallel to divide the current.

The current flowing through this resistor 12 is 2I2, and the power supply current is ■1+
12, the coil 101 is not in parallel with the resistor.
■1+■2, coil 102 in parallel with resistor 12
A current of ■1-■2 will flow through.

In this case, the current I2 flows in the upper and lower coils 101 and 102 in the same direction, generating a vertical magnetic field, and the current I2 flows in the upper and lower coils 101 and 102 in the same direction.
1 and 102 flow in opposite directions, generating a horizontal magnetic field.

Therefore, in the example of FIG. 5, one side 102 of a pair of vertical magnetic field coils
A horizontal magnetic field can also be generated by connecting a resistor 12 in parallel to .

The magnitude of the horizontal magnetic field can be adjusted by changing the value of the resistor 12.

Although a resistor is used in this embodiment, the same effect can be obtained by using a circuit element such as a reactor.

FIG. 6 shows an example in which the present invention is implemented in a case where there is a rewinding coil 14 as shown in FIG.

In this embodiment, the coil is rewound for each block, but
The coil on the opposite side with respect to the horizontal center and the unwinding coil are each short-circuited by a resistor 16.

In this example, the resistors 16 are connected in order to make the shunt ratio of each coil the same, but the distribution of the vertical magnetic field and horizontal magnetic field can also be changed by changing the resistance values separately.

Alternatively, only one resistor may be inserted in parallel at both ends of the series coils.

In this example, a coil with 20 turns per block is used, and a vertical magnetic field of about 1000 Gauss is obtained by passing a current of 10 KA, but when the vertical magnetic field is asymmetrical as in the present invention,
A horizontal magnetic field of up to about 200 Gauss can be generated.

On the other hand, contrary to the previous example, a vertical magnetic field can be generated by passing current in the same direction up and down to a coil installed for a horizontal magnetic field.

However, in general, the horizontal magnetic field required for a nuclear fusion device is much smaller than the vertical magnetic field, so a horizontal magnetic field coil that is too large is not used.

Regardless of its name, the coil shown in the present invention that simultaneously generates a vertical magnetic field and a horizontal magnetic field is essentially a vertical magnetic field coil that can also generate a horizontal magnetic field.

FIG. 7 shows an example in which the present invention is applied to vertical magnetic field coils 171 and 172 having unwinding coils 181 and 182, similar to FIG.

In this example, each block is provided with an intermediate tap, and rewinding is performed for each tap.

If the required horizontal magnetic field is very small compared to the vertical magnetic field, only one pair of shunt resistors 20 or the unwinding coil resistor may be omitted, allowing fine adjustment.

If a relatively large horizontal magnetic field is required, a pair of resistors 21 may be added.

FIG. 8 shows another example of application of the present invention.

In this example, a tap 24 is provided on one coil 222 without using a shunt resistor, and by switching the tap 24, the number of turns of the upper and lower coils 221, 222 is changed, creating an imbalance in the magnetomotive force and generating a horizontal magnetic field. .

Assuming that the current {circle over (2)}, the total number of turns per block of the coil is N, and the number of turns up to the energized tap is N1, a horizontal magnetic field corresponding to the magnetomotive force FR per block is generated.

On the other hand, the vertical magnetic field is per block The strength is equivalent to the magnetomotive force F, r.

In this embodiment, although the strength of the horizontal magnetic field cannot be changed continuously, it has the advantage that no current shunting resistor is required.

According to the nuclear fusion device of the present invention described above, the fusion device is vertically symmetrical with respect to the horizontal axis extending perpendicularly to the torus center axis of the torus-shaped vacuum vessel that confines plasma therein, and 1 of the vacuum vessel
-The upper and lower vertical magnetic field coils that generate a vertical magnetic field parallel to the center axis of the lath have different magnetomotive forces, so the vertical magnetic field coils generate a vertical magnetic field and a horizontal magnetic field that stably confine the plasma. Therefore, there is no need to provide a coil dedicated to the horizontal magnetic field and a power supply, and a fusion device with a simple structure and high reliability can be obtained without increasing the size of the device.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing the outline of a nuclear fusion device, Figure 2 is a conceptual diagram showing the principle of vertical magnetic field generation, Figure 3 is a conceptual diagram showing the principle of horizontal magnetic field generation, and Figure 4 is an example of the present invention. FIGS. 5 to 8 are power supply circuit diagrams of vertical magnetic field coils showing other embodiments of the present invention. FIG. 1...Plasma, 2...Vacuum container, 3
...Toroidal coil, 51. 52. 10
1. 102. 171.172...Vertical magnetic field coil, 111,112...Power supply, 12,16
, 21... Resistance, 20... Shunt resistance,
24...Tap.

Claims (1)

[Scope of Claims] 1. A torus-shaped vacuum vessel that confines plasma therein, and a torus-shaped vacuum vessel that is vertically symmetrical with respect to a horizontal axis extending perpendicularly to the torus center axis of the vacuum vessel, and that each extends along the vacuum vessel. In a nuclear fusion device having at least one set of vertical magnetic field coils that are arranged and generate a vertical magnetic field parallel to the torus center axis of the vacuum vessel, the magnetomotive forces of the upper and lower vertical magnetic field coils are made to be different from each other. A nuclear fusion device characterized by: 2. The nuclear fusion device according to claim 1, wherein the current values of the upper and lower vertical magnetic field coils are different from each other. 3. The nuclear fusion device according to claim 2, further comprising a current shunt circuit for at least one of the upper and lower vertical magnetic field coils. 4. The nuclear fusion device according to claim 2, wherein power sources for the upper and lower vertical magnetic field coils are different from each other. 5. The nuclear fusion device according to claim 1, wherein the upper and lower vertical magnetic field coils have different turn ratios. 6. The nuclear fusion device according to claim 5, wherein at least one of the upper and lower vertical magnetic field coils is provided with a winding number switching tap.