Developing a cerium doped labr3 (Ce) detector designed with Monte Carlo simulations and its application in numen project

A gamma-ray calorimeter array is studied in the context of next phase of NUclear Matrix Elements of Nuetrinoless Double Beta Decay (NUMEN) project which takes place in LNS-INFN laboratories in Italy for this thesis. The study is done with Geant4 simulation toolkit which uses Monte Carlo method. Fast, inorganic scintillators are considered due to high flux of gamma-rays and neutrons coming from the beam-target interactions for NUMEN experiments. LaBr3(Ce), which has the best energy resolution in fast inorganic detectors, is the subject of this thesis. It is expected that the planned calorimeter array, which has the 2.8% energy resolution, must discriminate the de-excitation gammas of ejectiles and residual nucleus from gamma and neutron flux due to beam-target reactions. Although, there are other kind of reactions, double charge exchange (DCE) reactions are the main interaction to be observed. Both, possible geometries of gamma calorimeter array and minimum cross-sections of the DCE reactions are investigated. According to the final gamma calorimeter array geometry, the minimum cross-sections must be between 1.69 - 1.91 nb for the worst case scenario. The combined performance of Focal Plane Detector of MAGNEX spectrometer and the gamma calorimeter array will be crucial for NUMEN project.