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 '' x 1 '' NaI(Tl) scintillator detector (crystal + housing + photomultiplier tube material equivalent) exposed to gamma rays in the energy range from 20 key 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. (C) 2012 Elsevier Ltd. All rights reserved.