{TAIL ~ The wafers} are then removed from {HEAD ~ the reactor tube} and further processing is performed upon them 
{ TAIL ~ The wafers } are then removed from { HEAD ~ the reactor tube } and further processing is performed upon them
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH