JP2994697B2 - Railgun type accelerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a railgun type acceleration device applied to a nuclear fusion experiment device and the like.

(Prior Art) A conventional railgun type accelerator will be described with reference to FIG. 6. (1) is a gas gun type pellet injector, (6) (6)
Is a pair of rails of the rail gun part, (2) is an introduction pipe connecting the gas gun type pellet injector (1) and the rails (6) and (6) of the rail gun part, and (3) is each of the rails (6). Pulse shaping network for applying voltage between them,
(4) is a plasma, (5) is a pellet, (7) is a needle (electrode) embedded in the rail (6), and (8) is a discharge power source for converting the accelerating gas into plasma. Is injected by the gas gun type pellet injector (1), accelerated initially, and the rail (6) of the rail gun section
When the pellet (5) passes through the needle portion (7) and passes through the accelerating gas behind the pellet (5), plasma (4) is generated. The pellet (5) is additionally accelerated by the plasma (4).

FIG. 8 is an explanatory diagram showing the relationship between the pressure × the distance between the electrodes [Pa · m] and the spark voltage when the pressure × the distance between the electrodes is around 0.1 to 0.4 [Pa · m].

(Problems to be Solved by the Invention) In the conventional railgun type accelerator shown in FIG.
When electricity is supplied to the accelerating gas behind the pellet (5) by the needle (7) to generate plasma (4),
Unless the pressure of the accelerating gas and the electric power applied to the needle (7) (electric energy required for discharging) are properly adjusted, the accelerating gas does not break down and the accelerating gas does not turn into plasma. At this time, the relationship among the gas pressure, the applied voltage, and the distance between the electrodes generally follows the Passun's law shown in FIG. 7, and the following problem occurs when the distance between the electrodes is fixed. That is, (i) when the applied voltage is kept low and the power capacity of the discharge power supply (8) is kept small, it is necessary to keep the acceleration gas pressure low, so that the initial velocity of the pellet (5) becomes small.

(Ii) When increasing the acceleration gas pressure and increasing the initial velocity of the pellet (5), it is necessary to increase the applied voltage.
Therefore, the power supply capacity of the discharge power supply (8) increases.

The present invention has been made in view of the above problems, and aims at adjusting the accelerating gas pressure to a pressure suitable for discharge (plasmaization) even if the accelerating gas pressure required for initial acceleration is high. As a result, the power supply capacity of the discharge power supply required to convert the accelerating gas into plasma can be reduced.
It is another object of the present invention to provide a railgun type accelerator in which the acceleration gas pressure required for the initial acceleration can be set arbitrarily and the initial velocity of the pellet can be increased.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for generating a plasma by supplying a current to an accelerating gas behind a pellet initially accelerated by a gas gun type pellet injector. A gas gun-type pellet injector, the rail gun unit, which accelerates the plasma by an electromagnetic force generated by a voltage applied between a pair of rails of a rail gun unit and a self-magnetic field and additionally accelerates a pellet. An inlet pipe with a pressure adjusting mechanism for arbitrarily setting the acceleration gas pressure by increasing or decreasing the numerical aperture of the gas vent hole is provided.

(Operation) The rail gun type acceleration device of the present invention is configured as described above, and the pellets are injected from the gas gun type pellet injection device to between the rails of the rail gun portion via the introduction pipe with the pressure adjusting mechanism. At that time, the pressure of the accelerating gas, which initially accelerated the pellet, was reduced to a pressure suitable for discharge, that is, plasma, by a pressure adjusting mechanism of the introduction pipe, which can be arbitrarily set by increasing or decreasing the numerical aperture of the gas vent hole. Thus, the rear of the pellet follows the pellet. The accelerating gas that has entered between the rails of the rail gun is turned into plasma by a voltage (electric energy) from a power supply for discharge, and the plasma is accelerated by an electromagnetic force generated by a voltage applied between a pair of rails of the rail gun and a self-magnetic field. And increase the speed of the pellet.

(Embodiment) Next, the rail gun type acceleration device of the present invention will be described with reference to one embodiment shown in FIGS. 1, 2 and 3. (1) is a gas gun type pellet injection device, (6) and (6) are rail gun units. Rails,
(20) is an inlet pipe with a pressure adjusting mechanism connecting the gas gun type pellet injector (1) and the rails (6) and (6), and the inlet pipe with the pressure adjusting mechanism (20) is an inner inlet pipe section. (twenty three)
An outer introduction pipe portion (21), a number of gas vent holes (9) penetrating the inner introduction pipe portion (23) radially inward and outward,
A sealing material (22) attached to the inner peripheral surface of the outer introduction pipe (21); and a plurality of gas vent holes (10) penetrating the outer introduction pipe (21) radially inward and outward. , The outer introduction pipe (21) and the sealing material (22) can rotate around the inner introduction pipe (23) in the direction of the arrow (A). The acceleration gas pressure is set arbitrarily by increasing or decreasing the numerical aperture.

Next, the operation of the rail gun type acceleration device shown in FIGS. 1, 2 and 3 will be specifically described. The pellet (5) is injected from the gas gun type pellet injector (1) to the rail (6) (6) of the rail gun through the inlet pipe (20) with a pressure adjusting mechanism.
At this time, the pressure of the accelerating gas, which initially accelerated the pellet (5), was reduced by the pressure adjusting mechanism of the introducing pipe (20) to the accelerating gas pressure in the introducing pipe (20) to a pressure suitable for discharging, that is, plasma. Then, the rear of the pellet follows the pellet. That is, the outer introduction pipe (21) and the sealing material (2
2) is rotated around the inner introduction pipe (23) (see arrow (A)), and the outer introduction pipe (21) and the sealing material (22)
Align the gas vent hole (10) of the inside with the gas vent hole (9) of the inner inlet pipe part (23), and accelerate the gas in the inner inlet pipe part (23) with the gas vent hole (9) → the gas vent hole (10). → Outside introduction pipe (2
1) Release the gas to the outside (see Q), reduce the accelerating gas pressure inside the inner inlet pipe (23) to a pressure suitable for discharge, that is, plasma, and follow the pellet behind the pellet. Become. Then, the accelerating gas that has entered between the rails (6) and (6) of the rail gun is turned into plasma by the voltage (electric energy) from the discharge power source (8), and this plasma is generated between the rails (6) and (6) of the rail gun. Acceleration is caused by the electromagnetic force generated by the applied voltage and the self-magnetic field, and the pellet (5) is additionally accelerated.

FIG. 4 shows another embodiment. In this embodiment, the introduction pipe (20 ') with the pressure adjusting mechanism is connected to the inner introduction pipe (2).
3 '), an outer introduction pipe (21'), a number of gas vent holes (9 ') penetrating the inner introduction pipe (23') inward and outward in the radial direction, and the outer introduction pipe (21 '). ') And a sealing material (22') attached to the inner peripheral surface of the outer introducing pipe (21 ').
And the sealing material (22 ') moves around the inner introduction pipe (23') in the pipe axis direction (the direction of the arrow (B)) to increase or decrease the numerical aperture of the gas vent hole (9 ') and accelerate The gas pressure is set arbitrarily. Other actions are the first, second, third
This is the same as the embodiment in the figure.

(Effect of the Invention) As described above, the rail gun type accelerator according to the present invention causes the pellet to be injected from the gas gun type pellet injector through the introduction pipe with the pressure adjusting mechanism to between the rails of the rail gun unit. that time,
The pressure of the accelerating gas, which initially accelerated the pellets, is reduced to a pressure suitable for electric discharge, that is, plasma by a pressure adjusting mechanism of the introduction pipe which can be set to an arbitrary pressure by increasing or decreasing the numerical aperture of the gas vent hole. Therefore, even if the acceleration gas pressure required for initial acceleration is high, the acceleration gas pressure can be adjusted to a pressure suitable for discharge (plasmaization), and the power supply for the discharge power supply required for acceleration gaseous plasma conversion The capacity can be kept low. In addition, the acceleration gas pressure required for the initial acceleration can be arbitrarily set, and the initial velocity of the pellet can be increased.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of an introduction pipe section with a pressure adjusting mechanism of a railgun type accelerator according to the present invention, FIGS.
Fig. 4 is an explanatory view of the operation, Fig. 4 is a vertical sectional side view showing another embodiment, Fig. 5 is a vertical sectional front view thereof, Fig. 6 is a system diagram showing a conventional railgun type accelerator, Figs. FIG. 4 is an explanatory diagram showing a relationship between pressure × electrode tube distance and spark voltage. (1) ... gas gun type pellet injector, (4) ... plasma, (5) ... pellet, (6) (6) ... rail,
(20)… Introduction tube with pressure adjustment mechanism, (9) (10) (21)
~ (23) ... Pressure adjustment mechanism.

Claims (1)

(57) [Claims] An electric current is supplied to an accelerating gas located behind a pellet initially accelerated by a gas gun type pellet injection device to generate plasma, and the plasma is generated by applying a voltage applied between a pair of rails of a rail gun unit to a self-voltage. In a railgun-type accelerator that accelerates by an electromagnetic force generated by a magnetic field and additionally accelerates a pellet, the number of apertures of a gas vent hole is increased or decreased between the gas-gun-type pellet injector and the railgun to increase the acceleration gas pressure. A railgun type acceleration device characterized by interposing an introduction pipe with a pressure adjustment mechanism that can be arbitrarily set.