Probe Diagnostics and Optical Emission Spectroscopy of Wave Plasma Source Exhaust

Abstract

Wave plasma sources (WPSs) were first proposed in the 1970s for electric propulsion (EP), and these research and development processes culminated in the flight test in 2021 of the WPS-based thruster REGULUS. Recently, new approaches to WPS use have emerged—multiple schemes of EPs that can generate propelling forces in multiple directions within a single thruster head, regarded as a breakthrough technology for in-space propulsion systems (PSs). One of the concepts is the bi-directional wave plasma thruster that is based on the open-ended gas discharge chamber—the symmetrical system. Up to now, the WPSs based on the open-ended chambers have not been widely studied. In this paper, the plasma flow formed by the WPS based on the open-ended chamber was axially characterized using a retarding potential analyzer (RPA), Langmuir probe (LP), and optical emission spectroscopy (OES). The presence of the double-layer (DL) was confirmed by a drastic change in the plasma potential along the axis, and a specific impulse of 1100 s was indirectly measured. The measurement results show the potential of the WPS based on the open-ended chamber for efficient operations.

Computational and Experimental Modeling in Magnetoplasma Aerodynamics and High-Speed Gas and Plasma Flows (A Review)

“…In works [126][127][128][129], the process of interaction of a capillary discharge with a supersonic air flow was studied experimentally as well as by the theoretical method [130][131][132][133][134][135][136][137][138][139][140]. It is shown that, depending on the initial conditions (the power released in the discharge, the speed of the incoming air flow, the initial pressure in the channel, etc.…”

“…A hole with a diameter of 3 mm was made in the copper outer electrode (1), which is cone-shaped. In works [128][129][130][131], the process of interaction of a capillary discharge with a supersonic air flow was studied experimentally as well as by the theoretical method [132][133][134][135][136][137][138][139]. The maximum velocity of the plasma jet propagation along its axis is 300 m/s (at a pressure of 80 Torr in the chamber) and 450 m/s (at a pressure of 20 Torr).…”

Starting Modes of Bi-Directional Plasma Thruster Utilizing Krypton

“…Recently, several concepts of multidirectional plasma thrusters and thruster heads based on them have been proposed [21][22][23][24][25]. The most mature thruster heads, Hall-effect and ion, are proposed to have thrust vectoring capability by means of sectioned anodes for Hall-effect thrusters [21] and sectioned ion optical systems for ion thrusters [22].…”