A. Taploo
George Washington University, District of Columbia, United States
Keywords: propulsion, air-breathing, ion thruster, plasma, aerospace, ionization
This study investigates the self-neutralization mechanism of air ions extracted from an air-breathing plasma thruster to develop a charge-neutralization-based thruster for very low Earth orbit applications. Through a combination of 2D Particle-in-Cell Monte Carlo Collision simulations and experimental approaches, the research explores how positive and negative ions can achieve charge density cancellation at the thruster's exit. Experimental observations reveal a naturally occurring self-neutralized ion beam, challenging conventional understanding by suggesting a previously unnoticed self-neutralization phenomenon in vacuum-operating plasma thrusters. The study identifies that self-neutralization is influenced by pressure and altitude, with significant effects observed up to 100 km altitude. Additionally, the research proposes a novel theory that ion clouds can self-neutralize without extra electrons under certain pressure settings, supported by simulation and experimental evidence. This investigation also delves into the design and performance evaluation of a scramjet-type neutralizer-less configuration with air and Nitrogen gas. By utilizing a tunable energy circular arc electron source for plasma generation and a cusp magnetic field-based acceleration region, the thruster achieves efficient beam neutralization for thrust production, eliminating additional neutralization equipment.