Response function of a 12.7 × 10.16 cm² NaI (Tl) scintillation detector

Gamma spectrometry with thallium-activated sodium iodide crystal, NaI(Tl) has been widely used in many fields, especially in industries and in the measurement of environmental radioactivity. The response function of NaI (Tl) detectors to gamma-rays are essential in quantitative understanding or unfolding the spectrum. Monte Carlo based numerical computational technique has been widely used to estimate the response function of radiation detectors. This paper discusses the response functions of a 12.7×10.16 cm² NaI(Tl) detector to gamma-ray sources using Monte Carlo method. The gamma spectrometry system used in this study comprises of 12.7 x 10.16 cm² NaI (Tl) coupled with PMT and integrated electronic accessories coupled with 1 k MCA. The system has been calibrated using IAEA certified reference materials