DECAY KINETICS OF CE3+ IONS UNDER GAMMA-EXCITATION AND KRF EXCIMER-LASER EXCITATION IN CEF3 SINGLE-CRYSTALS

Measurements of the decay kinetics of regular Ce3+ emission in CeF3 single crystals have been performed under photo-excitation and gamma (Na-22 radioisotope) excitation. While flashlamp-excited photoluminescence decay is distorted mainly by the influence of the 'near-surface' traps, the multiexponential nature of the scintillation decay is explained using pair interaction of close-lying Ce3+ excited ions, which account for the discrete character of their distances. Measurements of the same photoluminescence decay under high-intensity laser excitation show a similar departure from exponentiality as in the case of scintillation decay and support the proposed model.