Discharge Characteristics of a 10 W-class Pulsed Plasma Thruster

An experimental study of a 10 W-class Pulsed Plasma Thruster (PPT) was conducted. A PPT is a type of electric thruster that generates thrust by using electromagnetic force to accelerate plasma, which is produced through arc discharge between two electrodes. PPTs primarily use solid propellants such as Teflon, allowing for propellant feeding without tanks and valves. Therefore, PPTs offer a simple structure, high reliability, and excellent cost-effectiveness, making them well suited for CubeSat propulsion systems. To enable pulsed-mode discharge, a control circuit is required including a DC-DC converter to charge the capacitor to a high voltage of approximately 1–2 kV and an ignition circuit to trigger the spark plug. Discharge parameters such as the total resistance, capacitance, and inductance of the discharge circuit affect the thruster performance; therefore, discharge characteristics should be investigated by analyzing the discharge current and voltage waveform. In this study, a 10 W class PPT with a rectangular parallel-plate geometry was developed to meet the performance requirements: 0.1 mN of thrust and 600 s of specific impulse. The experiment was carried out in a vacuum chamber with a diameter of 1.7 m and a length of 3.5 m at a base pressure of 9×10^-7 torr. The thruster performance was estimated by analyzing current and voltage characteristics at a discharge energy of 10 J and an operating voltage range of 1–2 kV. Detailed discharge characteristics of the 10 W class PPT will be presented.