Discharge and Plume Characteristics of ALFVEN Thruster

This work presents discharge and plume measurements of the ALFVEN-4050 RF plasma thruster using argon and krypton propellants with a focus on the discussion of different electrical configurations on the thruster, i.e., floated and ground thruster body. Langmuir probe and RPA diagnostics show a detailed evolution of the electron temperature with the gas flow rate and the impact of different electrical configurations. A strong correlation between thruster potential, electron temperature, and imaginary impedance. At a specific gas flow rate condition, a dual-energy population appears in the ion beam, indicating double-layer formation and ambipolar acceleration. Thrust measurements show reduced efficiency at higher flow rates, suggesting a reduction in power contribution to acceleration processes. These results provide a clear picture of the discharge performance and ion acceleration in a low-power RF plasma thruster, guiding the future optimization for efficient electrodeless propulsion