The High Luminosity programme at Large Hadron Collider implies increasing of luminosity up to 10³⁴ см^-2 с^-1, which is requires an upgrade of LHCb detector’s subsystems in particular the electromagnetic calorimeter (ECAL). The increased instantaneous and integrated luminosity will result in very high particle density and radiation doses in the central area of the detector. In such new conditions the renewed calorimeter has to satisfy the requirements of LHCb experiment to high quality of energy measurements and cell’s size, as well as time resolution to correctly assign electromagnetic showers to primary vertices. This work is related to R&D of radiation hardness module of the electromagnetic calorimeter of the LHCb experiment which allows to save energy resolution at the level of 10% /√E, reach time resolution at the level of few tens of picosecond and provides the stable work at increased radiation dosed up to 100 MRad. The research includes studies of scintillating materials, in particular irradiation measurements, simulation studies of the energy resolution of the different configurations of the module to find the optimal, assembling of the modules, and beam test studies of the performance of various ECAL module prototypes to find the optimal detector layout.

(based on the materials of the thesis for the degree of the Candidate of Physics and Mathematics)