Experimental investigations in acceleration characteristics of micro pulsed plasma thruster fed with energy ≤1 J

As a promising candidate for micro/nano-satellite propulsion, the Micro-Pulsed Plasma Thruster (μPPT) requires a deep understanding of its acceleration mechanisms for effective optimization. This paper experimentally investigates these mechanisms. The μPPT’s low ionization efficiency and high neutral gas density result in the dominance of Electrothermal (ET) acceleration. Temporally, the first discharge cycle is dominated by Electromagnetic (EM) acceleration, while subsequent cycles are governed by ET effects. Owing to the circuit’s oscillatory nature, EM acceleration is prominent during the first and third quarter-cycles of the initial discharge. Spatially, the cathode side is dominated by EM acceleration, whereas the anode side is dominated by ET acceleration. This study elucidates the spatiotemporal variation of acceleration mechanisms within the μPPT and identifies a critical circuit limitation in small parallel-plate configurations: the significant energy loss induced by multi-cycle discharge oscillations.