Microtheory of scintillation in crystalline materials

Abstract

The review of the processes in solid state scintillators is presented. All steps of the transformation of energy in scintillators (production of secondary electronic excitations, thermalization, migration and recombination, photon emission) are observed. The processes at these steps are characterized by quite different spatial and time scales. These scales differs for various classes of scintillators, depending on electron structure of conduction and valence bands, energy position of core levels, phonon spectrum, presence of activators and dopants. Therefore the microscopic structure of electronically and vibrationally excited regions is material dependent. In general this structure is characterized by high non-homogeneity. For instance, in crystals consisted from heavy ions with several low-energy core bands the effect of the clusterization of secondary electronic excitations plays important role in formation of new emission centers. We discuss the estimation of the scintillation yield, non-proportionality, energy resolution and decay characteristics based on the analysis of elementary processes in scintillators.