Validation of detection efficiencies of NaI(Tl) scintillation detector in the
energy range of 80–1332 keV

Amity Institute of Nuclear Science & Technology (AINST), Amity University Uttar Pradesh (AUUP) in technical collaboration with the Center for Nuclear Security Science and Policy Initiatives (NSSPI) at Texas A & M University (TAMU), Oak Ridge National Laboratory (ORNL) and financial assistance from Defense Threat Reduction Agency (DTRA), jointly established the Nuclear Security Educational Laboratory. Detectors play a significant role in quantification of radiation irrespective of their applications in many different fields namely health physics, industry, energy, and environmental application. Consideration must also be given to efficiency of these devices as no detector can have 100% efficiency. It can vary with the volume and shape of the detector material, absorption cross-section in the material, attenuation layers between source and detector, and distance and position from the source to the detector. However, absolute efficiency of the detector depends on detector properties and also on the details of the counting geometry. In the present work, a straightforward analytical for the computation of total and full-energy peak efficiencies formulation using Osprey MCA based NaI (Tl) detector ranging energies from 80 to 1332 keV are presented. To obtain the energies various standard gamma ray sources supplied by BRIT, India were used. The variation of detection efficiency with the gamma ray energy and detection distance has also been investigated. Moreover, these experimental results are compared with the existing literature for conformity.