Some features of ionizing radiation energy losses in organic polycrystalline and composite scintillators

New types of organic scintillators (polycrystals and composite scintillators) have been developed and compared with organic single crystals. Polycrystals and composite scintillators were prepared from different grain size fractions obtained by grinding a single crystal with high structural perfection at low temperature followed by sieving. Composite scintillators were prepared by adding specific grain size fractions of stilbene to an optically transparent glue. The results of measurements are in good agreement with track formation data for organic scintillators, by which the scintillation signal in tracks of ionizing particles is mainly formed in the diffusion-controlled annihilation process of triplet exited molecules of a scintillator. Measured values of light yield and calculated density of excitation in tracks of alpha particles allow an estimation to be made of the quenching effect in the different scintillators.