Multiscale Approach to Estimation of Scintillation Characteristics

This work is directed to analysis and description of the factors which determine the efficiency of inorganic scintillators. The interconnection of different stages of track formation and relaxation is analyzed. The hierarchy of the scales of different processes in scintillators is discussed. The main attention is paid on the evolution of energy and spatial distribution of excitations in the excited region in scintillators. Different types of recombination - geminate and stochastic - and their features are considered, both in cases of low and high concentration of excitations and impurities. The spatial structure of the track after thermalization is discussed, with discriminating high-energy and low-energy part of the track of ionizing particle. Main features of thermalization and formation of thermalization length in different types of crystals with simple and complex structure and with different phonon spectrum are considered. The peculiarities of these processes in binary and complex halides and the estimation of limits of scintillator efficiency in these crystals are reviewed. Possible mechanism based on Auger relaxation of core hole which enhances the yield in CsI is proposed. The estimations of limiting factors for traditional alkali halide crystals and the perspectives of complex halides are discussed.