A simple approach to determine the radioactivities of nuclides with 200–2000 keV γ ray(s) in the absence of efficiency calibration standard

By combing 4π liquid scintillation (LS) and γ spectrometry, we proposed a new approach, which is based on the linearity of the energy and the efficiency of coaxial HPGe detectors in logarithmic coordinates, to determine the radioactivities of nuclides with 200–2000 keV γ ray(s). In this approach, the multi-gamma-ray nuclide 152Eu has been applied to obtain the slope of energy-efficiency line. Meanwhile, the intercept of the energy-efficiency line is obtained by determining the 661.657 keV γ ray radiation of 137Cs whose radioactivity is determined by 4π LS. For the fixed source-detector geometry of this study, the energy-efficiency line is: lgɛγ = −0.9503lgEγ + 0.5224. This simple approach is promising to be used to determine the radioactivities of all the nuclides which emit γ ray(s) with the energy (energies) between 200 and 2000 keV in the absence of efficiency calibration standard. The relative standard deviation of the approach is about 5.7%.