A POSITRON LIFETIME SPECTROMETER WITH BaF2 SCINTILLATORS

W. Osoba

Institute of Physics, Silesian University, Uniwersytecka 4, 40-007 Katowice, Poland


A conventional slow-fast coincidence positron lifetime spectrometer is presented. Two cylindrical BaF2 crystals have been used as scintillators coupled to Philips XP-2020 Q photomultiplier tubes. The spectrometer has been used to measure the lifetime of positrons in metals (Al and Cu single crystals, and Ni), and in polymers (kapton and polymethyl methacrylate).