The Model for Luminescence Center Excitation in PbWO_{4}

The luminescence and transient absorption of PbWO$\text{}_{4}$ crystals were studied. The electron beam (10 ns, E≈270 keV) was used as excitation source. The kinetics of luminescence is complicated - the prompt rise of luminescence intensity is followed by a slow (τ$\text{}_{r}$≈100 ns) rise. The luminescence decay at 80 K is nearly exponential with τ$\text{}_{d}$≈4.0- 4.5 μs. The decay kinetics of transient absorption at 3.5 eV can be described roughly by two exponents with time constants τ$\text{}_{1}$≈100 ns and τ$\text{}_{2}$≈4.0 μs. A common process responsible for absorption relaxation and luminescence rise is suggested. The luminescence center excitation occurs during recombination process via Pb$\text{}^{2+}$ excited state formation and subsequent energy transfer to WO$\text{}_{4}^{2-}$ group.