CCD images of Hall effect thruster plume dynamics after ultrafast current ignition

The dynamic behavior of the Hall effect thruster plasma plume is investigated after ultrafast current ignition driven by a metal-oxide-semiconductor field-effect transistor MOSFET power switch. Time-resolved optical measurements performed with a gated intensified charged coupled device (CCD) camera allow to reconstruct the plume temporal features. Images of the ion beam reveal oscillations in plasma light intensity linked to "breathing" instabilities. The observed periodic variations of the beam divergence originate from the displacement of the ionization layer within the thruster magnetic barrier.