Validating a Plasma Momentum Flux Sensor to an Inverted Pendulum Thrust Stand

The accuracy of a plasma impact force sensor was compared with that of the more commonly used inverted pendulum thrust stand using a 5 kW Xe Hall effect thruster. An improved plasma momentum flux sensor was designed and constructed based on a previous design. Real-time force measurements were made with both the plasma momentum flux sensor and the inverted pendulum thrust stand. The plasma momentum flux sensor measured the force exerted onto it by the Hall effect thruster exhaust plume with a resolution of 0.1 mN and an average discrepancy of 2% compared with thrust stand measurements. Experiments were completed using a 9 m by 6 m cylindrical vacuum chamber. The total force from the Hall effect thruster was modulated from 34 to 356 mN by varying both the anode voltage, from 150 to 500 V, and the neutral Xe gas flow rate, from 5 to 15 mg/s.