JPH0573915B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electric propulsion device mounted on a spacecraft flying in outer space, and in particular to an electric propulsion device that generates thrust by electrostatically accelerating charged particles. Regarding the ion engine obtained.

[Conventional technology]

Conventionally, this type of ion engine ionizes the propellant to create a main plasma 7, as shown in Figure 2.
In order to generate the neutralizer plasma 8, an electroded discharge using an electrode was utilized. That is, in the figure, the main plasma 7 that supplies electrostatically accelerated ions for the purpose of obtaining the thrust of the ion engine further accelerates the electrons generated by the main hollow cathode 21 to the anode 20. It is generated by the impact of accelerated electrons and propellant along the way. Further, after the ions have flowed out from the ion engine, the neutralizer plasma 8 that supplies electrons flowing out with the flow of ions in order to maintain the electrical neutrality of the ion engine itself is generated using the neutralizer hollow cathode 22. Ta. In the process of generating the main plasma 7 and the neutralizer plasma 8, conventional ion engines utilize electric discharge using electrodes.

[Problem to be solved by the invention]

The conventional ion engine mentioned above uses electric discharge using electrodes, but since the electrodes wear out as they discharge, the life of the ion engine is limited by the life of the electrodes, and as a result, the conventional ion engine The disadvantage is that the engine has a relatively short lifespan.
Further, as shown in FIG. 2, in order to perform electroded discharge, the conventional ion engine has a main hollow cathode 21, a main cathode keeper 23, an anode 20, a neutralizer hollow cathode 22, a neutralizer keeper 24, etc. This has the disadvantage of being structurally complex. Furthermore, the reliability of the ion engine as a whole is low due to short electrode life and structural complexity.

[Means to solve the problem]

The microwave resonance heating type ion engine of the present invention generates a main plasma and a neutralizer plasma by microwave resonance heating, which has not been done in the past. No discharge electrodes are used in the process of generating the main plasma and neutralizer plasma by this microwave resonance heating.

〔Example〕

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a diagram showing the operating principle of an embodiment of the microwave resonance heating type ion engine of the present invention. In the figure, microwaves generated by a microwave oscillator 12 and its driving power source 3 are introduced into a cavity 15 through a waveguide 14. The introduced microwaves cause standing waves within the cavity 15. The energy of this standing wave is transmitted through the bulkhead 13 and absorbed by the propellant located between the bulkhead 13 and the screen grid 10 and in the neutralizer 9, producing a main plasma 7 and a neutralizer plasma 8, respectively. Of the generated main plasma 7, positively charged ions are accelerated by a screen grid 10 and an acceleration grid 11 to form an ion beam. This becomes the thrust generated by the ion engine. On the other hand, negatively charged electrons in the neutralizer plasma 8 generated in the neutralizer 9 are mixed into the ion beam in order to maintain the electrical neutrality of the ion engine itself after the ions have flown out.

〔Effect of the invention〕

As explained above, the microwave resonance heating type ion engine of the present invention does not use a discharge electrode in the generation process of the main plasma and the neutralizer plasma, so the life of the ion engine is reduced compared to the conventional electroded discharge. It has the advantage that electrode life is not limited by electrode wear, as is the case with engines. Therefore, the microwave resonance type ion engine of the present invention has the effect of being able to have a longer lifespan than the conventional ion engine that uses electroded discharge. In addition, unlike conventional ion engines, it does not use a main hollow cathode, main cathode keeper, anode, neutralizer hollow cathode, neutralizer keeper, etc. to generate main plasma and neutralizer plasma, so it is structurally This has the effect of simplifying the process. Furthermore, the reliability of the ion engine as a whole is improved due to the long life of the electrodes and the simple structure.

[Brief explanation of the drawing]

FIG. 1 is a diagram of the operating principle of a microwave resonance heating type ion engine showing an embodiment of the present invention, and FIG. 2 is a diagram of the operating principle of a conventional ion engine that generates plasma using electroded discharge. In the figure, 1...PS1: Screen grid power supply (beam power supply), 2...PS2: Acceleration grid power supply, 3...
...PS8: Microwave oscillator drive power supply, 4...PS
6: Neutralizer heating power supply, 5... propellant supply tank,
6...Insulator, 7...Main plasma, 8...Neutralizer plasma, 9...Neutralizer, 10...Screen grid, 11...Acceleration grid, 12...Microwave oscillator, 13... Partition wall, 14...Waveguide, 15...Cavity, 16...PS3: Discharge power supply, 17...PS5: Main cathode keeper power supply, 18
... PS4: Main cathode heating power supply, 19 ... PS7: Neutralizer keeper power supply, 20 ... Anode, 21 ... Main hollow cathode, 22 ... Neutralizer hollow cathode, 23 ... Main cathode keeper, 24 ... ...It is a neutralizer keeper.

Claims (1)

[Claims] 1 In an ion engine consisting of a discharge vessel, a propellant supply system, an ion accelerating electrode, a microwave supply system, and an ion beam neutralizer, the main plasma is generated by introducing microwaves into the discharge vessel and neutralizer. and a microwave resonance heating type ion engine characterized by generating neutralizer plasma.