Investigation of the Magnetic Nozzle Configuration on the ALFVEN Thruster Performance

This work investigates the influence of magnetic field topology on the performance of the ALFVEN-4050 RF plasma thruster. Two magnetic configurations were tested: a standard (STD) field and a divergent magnetic nozzle (DMN). Plasma diagnostics using a Langmuir probe and retarding potential analyzer reveal that the DMN configuration yields higher electron temperatures and maintains more stable plume characteristics across varying flow rates, while exhibiting lower plasma density compared to STD. Ion energy distribution function (IEDF) measurements show significantly higher ion beam energies in DMN, indicating enhanced plasma acceleration. Thrust measurements confirm that DMN produces higher thrust and up to three times higher efficiency at low flow rates compared to STD. These findings demonstrate that magnetic nozzle shaping strongly affects power coupling and ion acceleration efficiency, providing a pathway for optimizing electrodeless plasma thrusters for improved performance.