Standardisation of 64Cu using a software coincidence counting system

• Standardisation realised by extrapolation method applied to 4π(PC)−γ coincidence.
• Digital method for optimal setting of coincidence parameters was used.
• Result with total standard uncertainty of 0.74% was obtained.

The activity of the radionuclide 64Cu was determined by the efficiency extrapolation method applied to 4π(PC)−γ coincidence counting. The standardisation was performed by software coincidence counting—a digital method for primary activity measurement that simplifies the setting of optimal coincidence parameters. The γ-ray-energy window, characterised by identical gamma detection efficiency related to the sum of EC and to the sum of beta decay branches, was found. This setting ensured a linear and zero slope extrapolation curve.