Determination of gamma-ray emission probabilities per decay of Ga-68

• The procedure for 4π(PC)β−γ primary standardization of 68Ga is described.
• Multiparametric fitting was performed for the extrapolation curve.
• Gamma-ray emission probabilities per decay were determined for seven transitions.

The measurement of the gamma-ray emission probabilities per decay of 1077 keV of 68Ga is presented. The standardization system consists of a gas-flow proportional counter in 4π geometry coupled to an HPGe detector for the gamma-ray detection. The gamma-ray emission probabilities per decay were measured in an HPGe gamma-ray spectrometer. The weaker gamma-ray intensities of 68Ga were measured in a relative way, making use of an uncalibrated ampoule of 68Ge–68Ga in radioactive equilibrium, and considering the absolute result from the 1077 keV gamma-ray.