The bi polar beam delivery system comprises {TAIL ~ a bi polar accelerator} configured to accelerate {HEAD ~ positive and negative ions} in the same direction making such a bi polar beam delivery system practical 
The bi polar beam delivery system comprises { TAIL ~ a bi polar accelerator } configured to accelerate { HEAD ~ positive and negative ions } in the same direction making such a bi polar beam delivery system practical
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH