Optimization of the Monte Carlo simulation model of NaI(Tl) detector by Geant4 code.

This work aimed to optimize the Monte Carlo simulation model of NaI(Tl) detector by Geant4 code. For detector modeling, the geometrical parameters are usually derived from the manufacturer's specification because of availability and convenience. However, the difference between real and nominal values in geometrical parameters of the detector can considerably affect the simulation results. To overcome this problem, a complete procedure for optimizing the geometrical parameters of the detector was proposed in this study. The results showed a good agreement between the simulated and experimental values, and the maximum discrepancy between the experimental and simulated values was 3.96%, 1.69%, and 3.50% for full-energy peak efficiency, energy resolution, and peak to Compton ratio, respectively.