Ablative z-pinch pulsed plasma thruster

The design, performance, and basic features of ablative pulsed plasma thrusters based on the z-pinch configuration are discussed through a series of experiments and numerical simulations. The motivation stems from the promise of the z-pinch configuration for increasing the thrust-to-power ratio and mass utilization efficiency above those of ablative thrusters with a conventional rectangular geometry. The performance of a series of ablative z-pinch pulsed plasma thrusters is characterized using a swinging-gate thrust stand and mass ablation measurements. The performance measurements are complemented by additional experimental diagnostics (current monitoring and high-speed photography) and numerical modeling in order to gain an understanding of the acceleration mechanism and provide direction for future design iterations. Three iterations in the design of the thruster result in thrust-to-power ratios ranging from 12-45 μN/W, with specific impulse and thrust efficiency values spanning 240-760 s and 2-9%, respectively. Numerical simulations show reasonable quantitative agreement with the experimental data and predict the existence of an optimal thrust chamber aspect ratio, which maximizes the thrust-to-power ratio.