The field from {TAIL ~ the magnetic duct} confines {HEAD ~ the plasma emission} from the cathodic arc allowing it to pass out the duct outlet with minimum current sink 
The field from { TAIL ~ the magnetic duct } confines { HEAD ~ the plasma emission } from the cathodic arc allowing it to pass out the duct outlet with minimum current sink
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH