Research of a high-frequency ion thruster with a four-electrode acceleration system

Аuthors

Peysakhovich O. D.^*, Melnikov A. V., Mogulkin A. ., Khartov S. A., Abgaryan V. K.

Research Institute of Applied Mechanics and Electrodynamics of Moscow Aviation Institute (RIAME MAI), Moscow, Russia

*e-mail: oleg_peysakhovich@mail.ru

Abstract

This article presents the results of testing a laboratory prototype of a high-frequency ion thruster with a four-electrode acceleration system, which can operate in two modes - a mode with increased thrust and a mode with increased specific impulse. To conduct the research, a laboratory model of the thruster with a cylindrical gas-discharge chamber and a plasma beam diameter of 150 mm was modi-fied. The four-electrode acceleration system was integrated into the classic design of the ion thruster with 3 electrodes. A comparison of the integral characteristics of the thruster with three- and four-electrode acceleration systems was made. Calculations of ion trajectories in 3- and 4-electrode ion-optical systems of thrusters are given. The fundamental possibility of operating the thruster with 4-electrode ion optics in two modes is shown. The principle of operation of the ion extrac-tion/acceleration system (IES) in ion thrusters is based on an electrostatic acceleration mechanism. The design of the IES is a multiparametric task that requires consideration of plasma parameters in the discharge chamber (DC), which directly affect its geometric configuration. Calculations of ion trajec-tories in the IES are typically performed using software tools [5] and [6]. The classical three-electrode IES consists of an emission electrode (EE), an accelerating electrode (AE), and an exit electrode (XE), sometimes referred to as a decelerating electrode (DE). The electric field strength between the EE and AE, together with the plasma density in the discharge chamber, determines the shape of the plasma boundary—the plasma meniscus. In qualification and flight ion thruster models, the EE potential typi-cally does not exceed 2000 V, while the AE voltage is set within about 10% of the EE potential. The extraction capability of the IES is significantly influenced by the thickness of the EE [3], whereas the thruster lifetime is largely determined by the thickness of the AE [7]. The use of a four-electrode ac-ce-leration system makes it possible to redistribute the accelerating voltage, for example 4 kV, among the emission, extraction, and accelerating electrodes. This reduces the potential drop in the interelec-trode gaps, for instance to about 2 kV, thereby providing additional margin against electrical break-down across the gaps.

Keywords:

four-electrode ion acceleration system, multi-mode electric rocket thruster, ion-optical system, high-frequency discharge, ion beam

References

1. Goebel DM, Polk JE, Wirz RE et al. Qualification of Com-mercial XIPS Ion Thrusters for NASA Deep Space Missions Jet Propulsion Laboratory. Pasadena: California Institute of Technology.
2. Lovtsov AS, Selivanov MYu, Tomilin DA et al. Main Results of the Keldysh Center's Developments in the Field of ER-DU. Izvestiya RAN. Energetika. 2020;(2):3–15. (In Russ.). DOI: 10.31857/S0002331020020077
3. Leiter HJ et al. Performance Improvement of Radiofre-quency Ion Thrusters - The Evolution of the RIT 15 Ion Thruster. IEPC-99-154. 26th International Electric Propul-sion Conference (17-21 Oct. 1999, Kitakyushu, Japan).
4. Peisakhovich OD, Mel'nikov AV, Mogulkin AI et al. High-frequency ion engine with a four-electrode ion-optical system. Inzhenernyi zhurnal: nauka i innovatsii. 2025;(4). (In Russ.).
5. Modeling of charged particle flows in ion-optical systems of ion engines (IOS-3D). 6.4.0.1. Gosudarstvennyi nauch-nyi tsentr Rossiiskoi Federatsii – federal'noe gosudar-stvennoe unitarnoe predpriyatie «Issledovatel'skii tsentr imeni M.V. Keldysha». (In Russ.).
6. The software package IGUN. (In Russ.).
7. Goebel DM, Katz I. Fundamentals of Electric Propulsion: Ion and Hall Thrusters (JPL Space Science & Technology Series). John Wiley & Sons; 2008. 486 p.
8. Mogulkin AI. Mechanical and mathematical model of de-formations of profiled electrodes of ion engines. PhD. the-sis. Moscow.2015. (In Russ.).
9. Svotina VV. High-frequency ion engine for the non-contact transportation of space debris. PhD. thesis. Moscow. 2023. (In Russ.).
10. Coletti M, Gessini P, Gabriel SB. A 4-gridded ion thruster for high impulse mission. the 31st International Electric Propulsion Conference (Ann Arbor, MI, USA, 2009).
11. Suvorov MO. Direct-flow air electric rocket engine traction unit. PhD. thesis. Moscow. 2018. 154 p. (In Russ.).