Tarasenko O. Generation of charge states and their energy exchange in organic solid scintillators.

The work is devoted to the problems of energy exchange of the charge states occurring in the regions of high density of radiation excitation, and an influence of this process on the radioluminescence pulse formation in organic solid scintillators. Organic single crystals, polystyrene scintillator, organic heterogeneous materials (polycrystalline and composite scintillators) are studied. For the first time the proposed approach considers the phenomenon of polarization as the factor which determines the features of the charge state energy exchange in ionizing particle tracks. It is shown that the degree of influence of the polarization interactions depends on the density of charge state pairs. The model description of a scintillation response formation in the approximation of the fast initial recombination of hot charge states is obtained. In contrast to Birks' formulas, this description contains parameters determined from the experiment. The mechanisms of the energy losses that take place directly after an excitation of organic molecular media by an ionizing particle are determined. The refined sequence of the energy exchange processes in the regions of high density of radiation excitation of organic molecular media takes into account an influence of the polarization interactions on the radioluminescence pulse formation. Keywords: polarization, charge state, recombination, ionizing radiation, particle track, organic scintillator, radioluminescence.