RU2766430C1 - Three-electrode ion-optical system - Google Patents

Abstract

FIELD: plasma technology.

SUBSTANCE: invention relates to the field of plasma technology, namely to ion systems, and can be used in the field of rocket and space technology in the development and assembly of ion-optical systems (IOS) of ion engines, ion guns and ion accelerators. According to the invention, to ensure ease of assembly, alignment, stability of operation and increase the resource of the ion-optical system, holes are made in the decelerating electrode so that they form groups of ion beams formed by the emission and accelerating electrodes, consisting of more than one hole, but less than the total the number of holes in the emission electrode and the accelerating electrode.

EFFECT: this three-electrode ion-optical system provides a simplified manufacturing, an increase in the resource of the ion-optical system according to the invention: in the decelerating electrode, the number of holes is made more than one and less than the total number of holes in the emission electrode and the accelerating electrode.

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Description

The invention relates to the field of plasma technology, namely to ion systems, and can be used in the field of rocket and space technology in the development and manufacture of ion-optical systems (IOS) of ion engines, ion guns and ion accelerators.

IOS is structurally and technologically the most complex and critical element of ion thrusters, ion guns and ion accelerators. It consists, as a rule, of emission (EE), accelerating (AE) and decelerating electrodes (SE), in which holes are made. One of the most important problems in the manufacture and assembly of the IOS is to ensure the accuracy of the alignment of the IOS electrodes.

Known IOS made of perforated EE and UE (grids) and one EE made in the form of a ring (USSR author's certificate No. 908193 "Ion source" and "Manned expedition to Mars" edited by A.S. Koroteev. - M: 2006, 318 pp. (pp. 149-152).

This option simplifies the manufacture of IOS, but will not allow to provide a high resource of IOS. The IOS resource is limited by the sputtering of the UE material. Since the accelerating electrode in the ion beam neutralization zone creates a high electrostatic field strength, this leads to an increase in the energy of the recharge ions incident on the RE (intercept current) and, consequently, to an increase in the erosion rate (ion sputtering) of the bridges between the RE holes (the RE erosion goes to surface facing the GE), which is reflected in the works of O.A. Gorshkov et al. Kholovskie and ion plasma engines for space vehicles. Moscow, Mashinostroenie, 2008, Edited by RAS A.S. Koroteeva s. 280 and R. E. Wirz, J. R. Anderson, D. M. Goebel, Fellow, IEEE and I. Katz "Decel Grid Effects on Ion Thruster Grid Erosion", IEEE TRANSACTION ON PLASMA SCEIENCE, VOL. 36, no. 5, October 2008. c. 2122-2129.

Also known are IOS made of three perforated electrodes (grids), while the number of holes in all electrodes (grids) is equal. (SW Patterson, A.K. Malik, MG Haines, DG Fearn "Characteriation of the discharge modes of a gas fed hollow cathode for a Kaufman-type ion thruster" and Ismat M. Ahmed Rudwan, NC Wallace, Michele Coletti, Stephen B Gabriel “Emitter depletion measurement and modeling in the T5&T6 Kaufman-type ion thruster”), this solution leads to an increase in the resource of the IOS, due to a decrease in the RE interception current, but significantly complicates the manufacturing technology of the IOS, in particular, it becomes more difficult to align the electrodes relative to each other.

Also, there is instability of work and the presence of breakdowns in the IOS with three perforated electrodes when this IOS enters the operating mode. This is due to the ingress of ions on the jumpers of the GE, UE and EE due to thermal deformations that occur during the heating of the IOS and lead to misalignment of the electrode holes.

The objective of the invention is to eliminate these disadvantages.

According to the invention, to ensure ease of manufacture and increase the resource of the IOS and the stability of operation, the number of holes in the SE is made more than one and less than the total number of holes of the EE and UE. Holes in the SE are made in such a way that groups of several ion beams obtained after passing through the holes of the RE are formed.

This method allows you to save the advantages of the IOS both with the design of the PG made in the form of a ring, and perforated PE, in which the number of holes is equal to the number of holes in the EE and UE:

- increase in the engine resource in comparison with the IOS with the design of the SE in the form of a ring;

- ease of manufacture, including the adjustment of the electrodes in comparison with the IOS with three perforated electrodes;

- more stable operation of the IOS when entering the operating mode in comparison with the IOS with three perforated electrodes. The proposed three-electrode ion-optical system is shown in Fig.1.

IOS (1) consists of: EE (2) with holes forming an aperture grid, UE (3) and EE (4) with holes different in number from EE and UE, but more than one, as well as fastener elements (5, 10) and ceramic insulators (6, 7, 8, 9).

In FIG. 2 and FIG. 3 shows the possible variants of the geometry of the holes of the SE.

Claims (1)

Three-electrode ion-optical system containing emission, accelerating and decelerating electrodes, characterized in that the number of holes in the decelerating electrode, forming groups of ion beams, is more than one and less than the number of holes in the emission electrode and accelerating electrode.

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