Time-resolved spectroscopy of CsI(CO₃) scintillator

The spectral-kinetics characteristics of short-living absorption and luminescence induced by an electron pulse irradiation (E_e=0.25 MeV, t_1/2= 7ns, W=2×10¹⁰÷4×10¹² electron/cm²) in CsI(CO₃) crystal are studied. It is shown that the scintillation pulse of CsI(CO₃) crystal is caused by the radiative annihilation of perturbed two-halogen excitons of two types, which are located in nearby impurity-vacancy dipole [CO₃ ^2--υ_a ⁺] anion sites. The processes responsible for post-radiation rise and decay of both CO₃ ^2--related luminescence bands with maxima at 2.8 and 3.2 eV are monomolecular with the thermal activation energy E_rise=0.1 eV and E_decay=0.05 eV. The cathodoluminescence pulse kinetics is discussed in the terms of the thermally assistant release of holes captured by CO₃ ^2--ions and the formation of CO₃ ^2--perturbed two-halide excitons.