Determination of Full Energy Peak Efficiency of NaI(Tl) Detector Depending on Efficiency Transfer Principle for Conversion Form Experimental Values

In this work we calibrated the NaI(Tl) scintillation detectors (5.08 × 5.08 cm and 7.62 × 7.62 cm) and the Full Energy Peak Efficiency (FEPE) for these detectors have been calculated for point sources placed at different positions on the detector axis using the analytical approach of the effective solid angle ratio. This approach is based on the direct mathematical method reported by Selim and Abbas [1,2] and has been used successfully before to calibrate the cylindrical, parallelepiped, and 4π NaI(Tl) detectors by using point, plane and volumetric sources. In addition, the present method is free of some major inconveniences of the conventional methods.