ИСТИНА

Intraband luminescence (IBL) is a fast luminescence occurring in insulating crystals on the stage of electron and hole thermalization after the interaction of ionizing radiation with these crystals This type of luminescence, in spite of its low quantum yield, is characterized by sub-picosecond rise time and picosecond decay time. Therefore, it could serve as a basis for fast timing for registration of ionizing radiation. The experimental search for such substances is quite time- and labor-consuming. In this regard, the development of a theoretical model of intraband luminescence, which would make it possible to estimate IBL parameters, such as quantum yield, spectrum and kinetics, using the band structure of the material, comes to the fore. It is expected that this model will simplify and accelerate the experimental search for substances with a high quantum yield of IBL. Within the framework of the present work, we develop a theoretical model of IBL for the simplified case of multiple parabolic branches of the electron dispersion law in the conduction band of insulating crystal. Both first order processes (electron-photon and electron-phonon) and second order ones (electron-phonon-photon) are taken into account for the model of multiple parabolic branch band. The quantum yield of CsI is estimated using Monte-Carlo technique to be of the order of 30-100 photons per MeV.