Abstract
The ion plume of a 72mm diameter Hall Effect Thruster operated on mixtures of xenon/nitrogen and xenon/air is investigated by means of a Wien filter (or E x B probe). The dependence of the velocities of the plume ions (Xe⁺, Xe²⁺, Xe³⁺, O₂⁺, O⁺, N₂⁺ and N⁺) on the operating parameters of the thruster (anode voltage, anode power, mass flow rate and magnetic field) is explored. The most probable ion acceleration voltages, the ion current and density fractions of the multi-propellant, multi-species ion beam, are computed from the Wien filter spectra through a dedicated post-processing analysis. The knowledge of these properties is fundamental for understanding the contribution of each ion species to the propulsive performance metrics of the thruster when operated on these molecular gas mixtures.