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