It will be appreciated that {HEAD ~ a thermal evaporation system} may be employed instead of {TAIL ~ the electron beam evaporation system} 
employed instead of
It will be appreciated that { HEAD ~ a thermal evaporation system } may be employed instead of { TAIL ~ the electron beam evaporation system }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL