Joint Institute for Nuclear Research, Russia

On the based Geant4, we investigated some optical properties of inorganic GSO and LYSO crystals. We also investigated the losses of emission of photons in the GSO crystal on the basis of SLitrani. We have made the simulation of the losses of light output along the crystal length on the  basis of SLitrni and made similar experimental measurements the losses of light output along the crystal length on the basis of JINR precision measuring setup.