The present work used the efficiency transfer method used to calculate the full energy peak efficiency (FEPE) curves of the (2"*2" & 3"*3") NaI (Tl) detectors based on the effective solid angle subtended between the source and the detector. The study covered the effect of the self attenuation coefficient of the source matrix (with a radius greater than the detector's radius) on the detector efficiency. 152 An Eu aqueous radioactive source covering the energy range from keV up to keV was used. In this study an empirical formula was deduced to calculate the difference between the measured and the calculated efficiencies [without self attenuation] at low and high energy regions. | Study on the effect of the self attenuation coefficient on a ray detector efficiency calculated at low and high energy regions
