Articolo in rivista, 2009, ENG, 10.1063/1.3152270

Anomalous Transport induced by Sheath Instability in Hall Effect Thrusters

F. Taccogna; S. Longo; M. Capitelli; R. Schneider

Istituto di Metodologie Inorganiche e dei Plasmi-CNR, Bari; Dipartimento di Chimica, Università degli Studi di Bari; Max Planck Institute fur Plasmaphysik, Greifswald

It is well recognized to ascribe the anomalous cross-field conductivity inside Hall-effect thrusters to fluctuation-induced transport due to gradient-driven instabilities (Rayleigh or electron drift) and to electron-wall interaction (near-wall conductivity). In this letter, we have performed numerical experiments showing the possibility of another mechanism inducing azimuthal fluctuations: the lateral sheath instability. It is created by a negative differential resistance of the current-voltage I-V characteristic of the floating wall as a consequence of high secondary electron emission. The contribution from this effect to the anomalous axial current is calculated and it accounts of more than 80% of the experimental value.

Applied physics letters 94 (25), pp. 251502–?

Keywords

CNR authors

Capitelli Mario, Longo Savino, Taccogna Francesco

CNR institutes

NANOTEC – Istituto di Nanotecnologia