Abstract
Well-type NaI(Tl) detectors are beneficial for low-level photon activity measurements because of the near 4
π
solid angle that can be gained with them. The detection efficiency can differ with the source-to-detector system geometries, the absorption of the photon in the detector material, and attenuation layers in front of the detector face. For these purposes, the absolute efficiency and the coincidence corrections of the well-type sodium iodide detector have been measured at 0.121–1.408 MeV energy range (obtained from
152
Eu,
137
Cs, and
60
Co radioactive isotopes). The covenant between the experimental (present work) and the published theoretical values is good, with the high discrepancies being less than 1%.