76th Annual Gaseous Electronics Conference
Volume 68, Number 9
Monday–Friday, October 9–13, 2023;
Michigan League, Ann Arbor, Michigan
Session HR2: Electric Propulsion IV
10:00 AM–12:00 PM,
Thursday, October 12, 2023
Room: Michigan League, Michigan
Chair: Yevgeny Raitses, Princeton Plasma Physics Laboratory
Abstract: HR2.00002 : PIC-MCC Simulation of ExB Discharge in High-Frequency Excited Plasmas for Air-Breathing Electric Propulsion in VLEO
10:15 AM–10:30 AM
Abstract
Presenter:
Mammadbaghir Baghirzade
(The University of Texas at Austin)
Authors:
Mammadbaghir Baghirzade
(The University of Texas at Austin)
Laxminarayan L Raja
(The University of Texas at Austin)
The present work concerns a magnetized high-frequency (HF) excited plasma discharge as an ionization source for extremely rarefied N2 environments (≤ 0.1 mTorr) encountered in Air-Breathing Electric Propulsion (ABEP) for Very Low Earth Orbits (VLEO) satellites. The goal is to analyze the complex physics of high frequency ExB discharge under rarefied N2 gas conditions, which involves phenomena such as a cyclotron orbit, collision events, and radio frequency (RF) excitation. This analysis is particularly crucial as the precise mechanisms that govern the breakdown of molecular nitrogen and the sustainment of the plasma within these conditions remain unclear. To understand this phenomenon, a high-fidelity computational modeling based on 1D-3V Particle-In-Cell/Monte-Carlo Collision (PIC-MCC) method coupled with Maxwell’s equations is carried out. The model adopts a fully kinetic approach and resolves inter-electrode gap distance of 10 cm in the 1D computation. All three components of particle velocity (3V) are considered to precisely capture the complex effects of magnetic fields on particle dynamics and the scattering events that arising during collisions within high frequency ExB discharge. The design incorporates a parallel-plate configuration, with a steady magnetic field of 100 G applied parallel to the electrodes for effective plasma confinement. An examination of the parameter space, i.e., 100 V – 10 kV, at high excitation frequencies, 100 MHz - 1 GHz, and initial seed electron densities 2.5x1013 - 2.5x1017m-3 is investigated at background gas (N2) pressure of ≤ 0.1 mTorr, (≤ 1018 m-3). Furthermore, by tracking a trajectory of a selected electron, the dynamics of an individual electron and the collision events it experiences are analyzed under magnetized and unmagnetized conditions. It is observed that in the absence of a magnetic field, no ignition occurred regardless of the initial plasma density, excitation voltages or background pressure. At the lowest background pressure of 0.1 mTorr that has been studied, the ionization of N2 is achieved at the higher initial plasma densities of 2.5x1016 #/m3and 2.5x1017 #/m3 with excitation voltages of 2 kV, 5 kV, and 10 kV, excitation frequency of 100 MHz and magnetic field strength of 100 G.