An ion source with {HEAD ~ these combined properties} has higher ratio of {TAIL ~ ion beam current} to discharge current than end Hall ion source and wider range of discharge parameters than closed drift ion source 
An ion source with { HEAD ~ these combined properties } has higher ratio of { TAIL ~ ion beam current } to discharge current than end Hall ion source and wider range of discharge parameters than closed drift ion source
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD 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 OTH OTH OTH