Recommended Practice for Use of ExB Probes in Electric Propulsion Testing

An ExB probe is an electric propulsion plume diagnostic that has at its core a Wien filter. Ions entering the instrument experience perpendicular electric and magnetic fields, and opposing electric and magnetic forces, and are filtered based on their velocity. While the ExB probe can be used to estimate ion velocity distribution function, in the electric propulsion community, it is commonly used to measure plume current and species fractions. There are numerous probe designs, implementation and operation procedures, and data analysis approaches described and in use across the community. This paper provides recommendations and descriptions of best practices for design, implementation, and data analysis for the ExB probe, with a particular emphasis on Hall and Ion thrusters. This work contributes to the broader community goal to standardize the use of diagnostics in electric propulsion testing.