Wafer shaped shields may occupy {HEAD ~ positions} adjacent {TAIL ~ top and bottom wafers} to cause them to heat the same as other wafers in the rack 
adjacent
Wafer shaped shields may occupy { HEAD ~ positions } adjacent { TAIL ~ top and bottom wafers } to cause them to heat the same as other wafers in the rack
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH