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