luminescent target means , for converting to {TAIL ~ luminescence values} the photoelectron emission from {HEAD ~ test points}  
luminescent target means , for converting to { TAIL ~ luminescence values } the photoelectron emission from { HEAD ~ test points }
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH