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