It also reduces a length of ionization region and leads to {HEAD ~ a monochromatization} of {TAIL ~ ion beam energy} 
of
It also reduces a length of ionization region and leads to { HEAD ~ a monochromatization } of { TAIL ~ ion beam energy }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL