After ionization, {TAIL ~ all the ions} can be easily directed to {HEAD ~ the collection plates} by an electric field formed from the parallel plates 
After ionization , { TAIL ~ all the ions } can be easily directed to { HEAD ~ the collection plates } by an electric field formed from the parallel plates
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH