Numerical Simulation of the Primary Ion Beam and of the Flow of Secondary Ions in the Grid System of an Ion Thruster

Аuthors

Abgarian V. K.^1*, Akhmetzhanov R. V.^1**, Loeb H. W.^2***, Obukhov V. A.^1****, Cherkasova M. V.^1*****

1. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
2. Justus–Liebig–Universität, I. Physikalisches Institut, Heinrich–Buff–Ring 16, Gießen, 35392, Germany

*e-mail: vka.mai@mail.ru
**e-mail: ahmetzhanov1991@mail.ruv
***e-mail: Horst.w.loeb@expl.physik.uni-giessen.de
****e-mail: riame@sokol.ru
*****e-mail: maria-post@mail.ru

Abstract

Ion thruster relates to one of the electric propulsion types, in which the plasma-forming gas is accelerated in the form of a beam of positively charged ions, subsequently neutralized by electrons at the thruster exit. One of the basic units of the ion thruster is the grid system designed to extract ions from the gas discharge plasma and to accelerate them up to the required speed. The slow secondary charge-exchange ions originate during the primary beam motion in the interelectrode gap and in the neutralization zone; they bombard the accelerating electrode, causing its erosion, which limits the thruster lifetime.
The article deals with the modeling of the formation of the primary ion beam and charge-exchange ion flows in a three-electrode grid system. The purpose was to obtain a detailed pattern of the primary ion trajectories for the selection of optimal configuration of the grid system providing necessary parameters of the beam efflux, as well as of the trajectories of the secondary ions for further modeling of the electrode erosion.
Modeling of trajectories of the primary beam ions was made by the software package IGUN. In addition, a program block was developed to simulate the trajectories of the secondary ions, using which an area was defined within the volume of the primary ion beam, from which the originating charge-exchange ions hited the accelerating electrode of the grid system. The results obtained can be used to calculate erosion of the accelerating electrode of the thruster grid system.

Keywords:

radio frequency ion thruster, ion-optical system, erosion, ion flux recharge, neutralization zone, space charge

References

1. Software developer of IGUN, http://www.egun-igun.com
2. Goebel D.M., Polk James E., Sandler I., Mikellides I.G., Brophy J.R., Tighe W.G., Chien Kue-Ru. Evaluation of 25-cm XIPS Thruster Life for Deep Space Mission Applications , Proceedings 31st International Electric Propulsion Conference, University of Michigan, USA, IEPC-2009-152, 200,13 p.
3. Obukhov V.A., Sosnovskij V.E. Materialy 5 konferenciji «Plazmennye uskoriteli i ionnye inzhektory», Moscow, Nauka, 1982, pp. 105-106.
4. Hasted J. Fizika atomnyh stolknovenij (Physics of atomic collisions), Moscow, Mir, 1965, 710 p.
5. Snyder J.S., Goebel Dan M., Hofer Richard R., Polk James E., Neil C., Wallace Huw Simpson. Performance Evaluation of the T6 Ion Engine, Proceedings of the 46^th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibition, AIAA 2010-7114, Nashville, TN, USA, 2010.
6. Trubnikov B.A. Voprosy teorii plazmy , Moscow, 1963, no. 1, pp. 98-182.

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