Time-Resolved ExB Probe Measurement of Hall Thruster Plasma

Abstract

Reconstruction of synchronized time-resolved ExB probe measurement is conducted on a Hall-effect thruster operating on krypton at three power levels. The synchronization is implemented with an algorithm based on Fourier transfer functions between the discharge current and ExB probe measurements. The research serves as the baseline for future investigation of time-resolved ion velocity and charge state diagnostics for Hall-effect thrusters. ExB measurement is closely tied to both the ion velocity distribution function and charge-state distribution. The obtained reconstructed ExB probe signal is analyzed using parametric curve-fitting with the superposition of two Maxwellian distribution functions. The result of analysis qualitatively suggests the presence of temporal and spatial variation of charge-state distribution in the exhaust plasma. Future steps for improvement and further research are mentioned.