1. Nuclear Power Institute of China,Chengdu,Sichuan 610000,China
2. National Institute of metrology, Beijing 100029, China
3. University of Science and Technology of China, Hefei,Anhui 230027, China
4. National Defense Science and Technology Industry Ionizing Radiation Level I Metering Station, Beijing 102413, China
5.East China University of Techology, Nanchang, Jiangxi 330013, China
Abstract：The 4Πβ(PC)-γ coincidence method is mainly used to achieve the absolute measurement of β-γ cascade decay radionuclide activity. This method generally measures the VYNS film source sample, This method is usually used to measure the VYNS film source sample, but its preparation process is complicated. This paper simplifies the source process. The source preparation process is optimized. The film source produced by the improved process is measured using a 4Πβ(PC)-γ digital coincidence system. The measurement results obtained by the efficiency extrapolation method show that the apparent efficiency of the new 60Co source reaches 93%, and the specific activity measurement results of the 10 sample sources are consistent within the range of 0.1%. By changing the resolution time, dead time and delay time on the digital compliance software, the influence of the parameter selection on the measurement results is studied, and the uncertainty of the 60Co nuclide activity measurement is evaluated.
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2020, Vol. 41 
