Modelling of Applied-Field Magneto Plasma Dynamic Thruster with Argon Propellant for CubeSat

The Magneto Plasma Dynamic Thruster (MPDT) is a type of electric propulsion system designed for spacecraft. It is primarily utilized in deep-space missions, characterized by prolonged low-thrust acceleration and minimal propellant requirements. MPDTs generate thrust by utilizing the force exerted on charged particles by an electromagnetic field. Traditionally, MPDT technology employs a high discharge current between two electrodes and a solenoid coil as the applied magnetic field. However, in this study, the high discharge current is replaced with a limited discharge current. This is achieved by using a capacitor bank to control the current flow between the electrodes. Additionally, the solenoid coils are substituted with a permanent magnet to serve as the applied field for thrust generation. The essential components of the MPDT include a power circuit comprising an electrolytic capacitor bank, which is compact and provides a limited voltage to regulate the current between the electrodes. The electrodes are made of copper (anode) and tungsten (cathode), with a permanent magnet positioned coaxially over the anode. The cathode is centrally located between the electrodes, and argon gas is chosen as the propellant due to its monoatomic nature which is injected into the system. Theoretically the thruster discharge current is calculated to match with the experimental results which is done later on. The performance of the thruster can be tested under vacuum conditions using experimental set up, with thrust measured using a load cell and the prototype MPDT can be evaluated for parameters such as discharge current, thrust, specific impulse, and efficiency. By measuring thrust at various discharge currents, the optimal operating conditions for the MPDT can be identified.