A scintillator, characterized in that it comprises {HEAD ~ crystals} of {TAIL ~ Pr1} xCexF3  
of
A scintillator , characterized in that it comprises { HEAD ~ crystals } of { TAIL ~ Pr1 } xCexF3
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH