A Hall probe diagnostic for low density plasma accelerators

Abstract

A Hall probe diagnostic was developed for use with plasma thrusters. The Hall generators were mounted at the end of a stainless steel tube heat exchanger. Ceramic cement and a Pyrex tube were used as radiation and particle flux shields, respectively. A thermocouple was used to monitor the temperature of the Hall generator. The low voltage output from the probe was amplified within one meter of the transducer to minimize the effect of noise pick up. A National Institute of Standards and Technology traceable Gaussmeter provided an absolute reference for calibration, and relative calibrations were performed both in a strong electric field and in situ during thruster operation to approximate the conditions in the discharge. The overall accuracy of the diagnostic was ±6 G.±6G. The probes were tested with a Hall-effect thruster, and provided sufficiently accurate data to estimate the magnitude of the closed-drift electron current. © 1998 American Institute of Physics.