Plasma density measurements inside a laboratory model Hall thruster using a resonance probe diagnostic
Plasma density measurements are made in the discharge chamber of the Plasmadynamics and Electric Propulsion Laboratory (PEPL) P5 laboratory model Hall thruster. A thruster operating condition of 300 V and 5.4 A is maintained throughout the experiment. A resonance probe diagnostic system is used for all measurements and axial positioning of the probe is accomplished using the PEPL High-speed Axial Reciprocating Probe (HARP) system. The P5 is mounted to a linear translational stage allowing for two-dimensional, spatially resolved plasma density measurements. A model incorporating the electron collision frequency and sheath capacitance is developed to interpret the resonance probe data. Data are presented at axial positions from the anode to 5 cm downstream of the exit plane and at radial positions across the width of the discharge chamber. The resonance probe measurements are compared to density measurements obtained with a floating double Langmuir probe.
