Validation of a NaI(Tl) detector's model developed with MCNP-X code

The Monte Carlo method was used to calculate the photon detection efficiency and energy resolution curves for a 1.5″ × 1″ NaI(Tl) scintillator detector (crystal + housing + photomultiplier tube material equivalent) exposed to gamma rays in the energy range from 20 keV to 662 keV. This work aims to design a precise computational model, based in Monte Carlo simulation, which can be used in practical application. The energy resolution curve was used to improve the response of the mathematical simulation of the detector. The detector was modeled with the MCNP-X code and the results were compared to experimental photopeak efficiency measurements of radiation sources. The results showed good agreement with the experimental data.

► We model NaI(Tl) detector using the MCNP-X code base in Monte Carlo simulation.
► We consider the model's detector as crystal, housing and photomultiplier tube.
► We validate the model with radiation sources by photopeak efficiency.
► We modify the active detector volume to validate the model.
► We use the experimental energy resolution curve to improve the response of the model.