Fast Camera Analysis of Plasma Instabilities in Hall Effect Thrusters Using a POD Method under Different Operating Regimes
Victor Désangles,
Sergey Shcherbanev,
Thomas Charoy,
Noé Clément,
Clarence Deltel,
Pablo Richard,
Simon Vincent,
Pascal Chabert,
Anne Bourdon
Affiliations
Victor Désangles
Laboratoire de Physique des Plasmas, CNRS, Ecole Polytechnique, Sorbonne Université, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, PSL Research University, F-91128 Palaiseau, France
Sergey Shcherbanev
Laboratoire de Physique des Plasmas, CNRS, Ecole Polytechnique, Sorbonne Université, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, PSL Research University, F-91128 Palaiseau, France
Thomas Charoy
Laboratoire de Physique des Plasmas, CNRS, Ecole Polytechnique, Sorbonne Université, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, PSL Research University, F-91128 Palaiseau, France
Noé Clément
Laboratoire de Physique des Plasmas, CNRS, Ecole Polytechnique, Sorbonne Université, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, PSL Research University, F-91128 Palaiseau, France
Clarence Deltel
Laboratoire de Physique des Plasmas, CNRS, Ecole Polytechnique, Sorbonne Université, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, PSL Research University, F-91128 Palaiseau, France
Pablo Richard
Laboratoire de Physique des Plasmas, CNRS, Ecole Polytechnique, Sorbonne Université, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, PSL Research University, F-91128 Palaiseau, France
Simon Vincent
Laboratoire de Physique, University Lyon, Ens de Lyon, University Claude Bernard, CNRS, F-69342 Lyon, France
Pascal Chabert
Laboratoire de Physique des Plasmas, CNRS, Ecole Polytechnique, Sorbonne Université, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, PSL Research University, F-91128 Palaiseau, France
Anne Bourdon
Laboratoire de Physique des Plasmas, CNRS, Ecole Polytechnique, Sorbonne Université, Université Paris-Sud, Observatoire de Paris, Université Paris-Saclay, PSL Research University, F-91128 Palaiseau, France
Even after half a century of development, many phenomena in Hall Effect Thrusters are still not well-understood. While numerical studies are now widely used to study this highly non-linear system, experimental diagnostics are needed to validate their results and identify specific oscillations. By varying the cathode heating current, its emissivity is efficiently controlled and a transition between two functioning regimes of a low power thruster is observed. This transition implies a modification of the axial electric field and of the plasma plume shape. High-speed camera imaging is performed and the data are analysed using a Proper Orthogonal Decomposition method to isolate the different types of plasma fluctuations occurring simultaneously. The low-frequency breathing mode is observed, along with higher frequency rotating modes that can be associated to rotating spokes or gradient-induced instabilities. These rotating modes are observed while propagating outside the thruster channel. The reduction of the cathode emissivity beyond the transition comes along with a disappearance of the breathing mode, which could improve the thruster performance and stability.
