{HEAD ~ magnetic poles} placed at exit part of ion source and a magnetic pole in a center of {TAIL ~ a discharge channel} in a form of protrusion with a magnet or electromagnet placed in a central magnetic pole 
{ HEAD ~ magnetic poles } placed at exit part of ion source and a magnetic pole in a center of { TAIL ~ a discharge channel } in a form of protrusion with a magnet or electromagnet placed in a central magnetic pole
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH