Study of a low-power micro coaxial pulsed plasma thruster with axial applied magnetic field

Pulsed plasma thrusters (PPTs) have been widely used in nano/micro-satellites in recent years. However, the efficiency of a low-power (<10 W) PPT is typically lower than 10%. Applied magnetic fields are widely used in electric propulsion to improve performance. However, few attempts have been made to use applied magnetic fields in low-power PPTs because of the high discharge current (kA), short pulse duration (μs), and oscillating current in the discharge process. The results of an experimental study on a low-power micro coaxial PPT with axial applied magnetic field are presented in this paper. The thrust, ablation, and discharge characteristics of the thruster are obtained under different applied magnetic fields. The results show a significant improvement in thruster efficiency. Using magnets that can generate magnetic fields of up to 0.3 T, 0.4 T, and 0.5 T result in efficiencies for the PPT of 15.6%, 24.7%, and 67.8%, respectively, which are 1.91, 3.03, and 8.34 times that in the absence of an applied magnetic field (8.1%). The results also show that the applied magnetic field has little influence on the discharge circuit and slightly affects the discharge characteristics and ablated mass bit (the consumption of propellant per discharge) of the thruster.