Abstract: Employing self-made radioactive reference source and LabSOCS (Laboratory Sourceless Calibration Software), the radioactivity of ¹³⁴Cs and ¹³⁷Cs of three simulated aerosol filters for IAEA intercomparison were determined by γ-spectrometry in 2019. The relative deviations between the measured results and the IAEA reference values were less than 4%. The coincidence summing correction factors for the five full-energy-peaks with high emission probability of ¹³⁴Cs were from 0.729 to 0.829. Ignoring coincidence summing correction in near geometry configuration may result in a deviation of more than 20%. The detection efficiency was significantly affected by the distance between the sample and the detector. This study can be applied for aerosol filter measurement of airborne effluent from nuclear power plants.

Key words: Simulated aerosol filter, Gamma-ray spectrometry, Coincidence summing correction