JP2746889B2 - Ion thruster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an ion thruster for controlling the orbit of an artificial satellite. (Prior Art) FIG. 5 shows the configuration of a conventional ion thruster. A x _e gas introduced into the discharge vessel 8 through the isolator 9 and hollow cathode 1 from the gas introduction system, the discharge chamber ionization plasma electrons accelerated by the release after the anode 2 collides from the hollow cathode 1 Generate The ions are given kinetic energy by the accelerating electrode 4,
After being neutralized by the electrons emitted from the neutralizer 6, they are emitted and become thrust of the ion thruster. Since the discharge vessel 8 is disposed on the high potential side (about 1 kV) of the acceleration electrode 4,
An insulator 9 for electrical insulation is provided between a low-potential (about 0 kV) side and a gas introduction system such as a gas cylinder.
FIG. 6 shows the configuration of a conventional insulator 9. The insulator 9 includes a plurality of alumina insulating rings 11 shown in FIG. 6 (b) in an alumina insulating container 10 shown in FIG. 6 (a).
The wire mesh electrodes 12 shown in FIG. 3 are alternately provided to reduce the pressure sequentially to prevent glow discharge. Since the starting voltage of the glow discharge depends on the pressure between the wire mesh electrodes 12, there is a wire mesh electrode 12 that causes a glow discharge depending on the gas pressure, and the number of wire mesh electrodes 12 is adjusted to prevent it. . If the number of wire mesh electrodes 12 is made sufficiently large, such troubles can be eliminated, but the size of the insulator 9 is increased.
It is unsuitable for space equipment. In particular, a large ion thruster requiring a plurality of gas inlets requires much time for adjustment, which is a major problem. (Problems to be solved by the invention) The present invention relates to a withstand voltage characteristic of an insulator (generation of glow discharge).
However, the present invention has been made in view of the fact that it strongly depends on the configuration of a wire mesh electrode, and an object thereof is to provide an ion thruster provided with an insulator that does not require much adjustment. [Structure of the Invention] (Means for Solving the Problems) The present invention provides a mechanism for adjusting the gas pressure inside or outside the insulator, and can move the pressure inside the insulator to a region where glow discharge is difficult to occur. An ion thruster characterized in that: (Operation) According to the present invention, since the pressure in the insulator can be adjusted without changing the wire mesh electrode, the starting voltage of the glow discharge can be easily set to a high pressure. (Example) Hereinafter, an example of the present invention will be described in detail. Note that the same reference numerals are given to the same components as those of the conventional device, and the description thereof will be omitted. As shown in FIG. 1, isolators ion thruster of the present invention, x _e gas pressure adjusting plate 14 and the third to the gas inlet side and the outlet side shown in FIG. 2 of a plurality with a suitable aperture ratio The gas pressure adjusting plate 15 shown in the figure is inserted, and the pressure in the insulator 9 is set near the region where the starting voltage of the glow discharge is high and the required gas pressure can be secured. Subsequent fine adjustment is performed by displacement of the flow passage hole due to rotation of the gas pressure adjustment plate 14 on the gas outflow side. Since the gas pressure adjusting plate 14 is provided with the thread 17 and the cut 16, the adjustment is easy. Where the cut
Reference numeral 16 is provided so that the tip of a screwdriver having a flat tip (eg, a commercially available flathead screwdriver or the like) is inserted into the insulator 9. The threading 17 is engaged with a groove provided in the insulator 9 into which the gas pressure adjusting plate 14 is inserted, and is fitted by rotating in a predetermined direction. With such a configuration, the gas pressure adjusting plate 14 is rotated along the groove of the thread 17 so that the flow passage hole provided in the gas pressure adjusting plate 14 is The gas pressure in the insulator 9 can be easily shifted,
It can be easily adjusted. When the insulator 9 is integrated with the discharge vessel 8 and is disassembled from the inflow side,
The gas pressure adjusting plates 14 and 15 are replaced, and fine adjustment is performed on the inflow side. Since the pressure in the insulator 9 can be adjusted by the gas conductance of the gas pressure adjusting plates 14 and 15, there is no need to replace the wire mesh electrode 12, and the adjustment time can be greatly reduced. FIG. 4 shows another embodiment of the present invention, in which a mechanism 18 for adjusting the gas pressure is provided separately from the insulator 9. The mechanism 18 for adjusting the gas pressure is composed of a plurality of gas pressure adjusting plates 14 for varying the gas conductance, and adjusts the pressure in the insulator 9 by any of the flow passage holes by rotation. The mechanism for adjusting the gas pressure
It is easier to adjust 18 if it is provided on the gas outflow side of the insulator 9.
The gas pressure adjusting plate 15 shown in FIG. 1 and the gas pressure adjusting plate 14 shown in FIG.
May be used together. Although _xe is used as the introduced gas, it is not limited to _xe gas. Although an electron impact type of a cusp magnetic field confinement method is used as the ion thruster, any type using the insulator 9 may be used, and the type is not limited to this type. [Effects of the Invention] According to the present invention, it is possible to realize a simple insulator for adjusting a region where glow discharge is difficult, and to manufacture a highly reliable ion thruster.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention, FIGS. 2 and 3 are perspective views showing components of the embodiment of the present invention, and FIG. FIG. 5 is a configuration diagram of a conventional ion thruster, and FIG. 6 is a configuration explanatory diagram of a conventional insulator. 1 hollow cathode 2 anode 3 magnet 4 accelerating electrode 5 thruster case 6 neutralizer 7 baffle 8 discharge vessel 9 insulator 10 ... Insulating container 11 ... Insulating ring, 12 ... Wire mesh electrode 13 ... Metal ring, 14,15 ... Gas pressure adjusting plate 16 ... Cut, 17 ... Threading 18 ... Gas pressure adjusting mechanism

Claims (1)

(57) [Claims] A gas introduction system for introducing gas into the discharge vessel, an insulator provided between the gas introduction system and the discharge vessel, an acceleration electrode for accelerating ions emitted from the discharge vessel, and the gas introduction system. A mechanism for adjusting the gas pressure of the gas introduced from the gas introduction system between the discharge vessel and the discharge vessel. 2. The mechanism for adjusting the gas pressure is provided with one or a plurality of gas pressure adjusting plates on the gas inflow side and / or the outflow side or any one of the insulators, either integrally with or separately from the insulators. 2. The gas pressure in the insulator according to claim 1, wherein the gas pressure in the insulator is changed by using an aperture ratio of each plate with respect to a gas flow and, when there are a plurality of plates, displacement of a flow passage hole due to rotation. Ion thruster. 3. 3. The ion thruster according to claim 2, wherein the gas pressure adjusting plate on the outflow side is cut and threaded so that the gas pressure adjusting plate can be screwed.