Timing properties of GSO, LSO and other Ce doped scintillators

Light pulse shape, number of photoelectrons per energy unit and time resolution for a 1 × 1 × 1 cm3 GSO crystal coupled to a XP2020Q photomultiplier were studied and compared with similar measurements performed earlier on a LSO crystal. The observed time resolution of the time spectra, FWHM = 700 and 965 ps for the energy threshold set at 1 and 100 keV on the 60Co γ-spectrum, are inferior compared to those for LSO because of the slow rise of the light pulse of GSO and a lower light yield. The time resolution obtainable with the GSO and LSO crystals is discussed based on the Hyman theory of timing. It allows discussion of the advantages and limitations of new Ce doped scintillators in fast timing.