Gas molecules containing one of the isotopes are then deflected from {HEAD ~ the other gas molecules} in {TAIL ~ the stream} and thus physically separated 
in
Gas molecules containing one of the isotopes are then deflected from { HEAD ~ the other gas molecules } in { TAIL ~ the stream } and thus physically separated
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH