Topic/Type: 1.6 Plasma-based devices, Poster

Two examples of space charged saturated sheaths: Hall thruster discharge and negative ion source.

F. Taccogna

IMIP-CNR, Istituto di Metodologie Inorganiche e di Plasmi, Bari, Italy

The plasma-wall transition region in the presence of an emitting surface can present singular and complex behaviors. This is the case of sheath with a strong secondary electron emission coefficient (Hall thruster discharge) and the extraction region of an hybrid negative ion source with caesiated surface. In both cases a strong negative charged fluxes from the wall are responsible of double layer potential structure, sheath instability and anomalous electron conductivity (Hall trhuster) and low negative ion extraction probability (negative ion source). This work represents a numerical study (2D PIC-MCC models) of the two previous exemples.