Hall Thruster and VASIMR VX-100 Force measurements using a Plasma Momentum Flux Sensor

Abstract

The accuracy of a plasma impact force sensor was compared to that of the more commonly used inverted pendulum thrust stand using a 5 kW Xe Hall effect thruster (HET). An improved plasma momentum flux sensor (PMFS) was designed and constructed based on a previous design. Real-time force measurements were made with both the PMFS and the inverted pendulum thrust stand. The PMFS measured the force exerted onto it from the HET exhaust plume with a resolution of 0.1 mN, and an average discrepancy of 2% compared to thrust stand measurements. Experiments were completed using a 9 m by 6 m cylindrical vacuum chamber. The total force from the HET was modulated from 34 mN to 356 mN by varying both the anode voltage, from 150 V to 500 V, and the neutral Xe gas flow rate from 5 mg/s to 15 mg/s. Initial force measurements from the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) VX-100 are analyzed and compared to RPA data.