Absolute disintegration rate measurements of Ga-67

The procedure for determining the 67Ga disintegration rate by means of a 4πβ–γ coincidence system is described. The main difficulty with this radionuclide is the presence of a meta-stable state with a half-life of 9.1 μs and a total internal conversion coefficient of 0.89. This required several measurements using different electronic dead-times to correct for detection of delayed events. Gamma spectrometry measurements by a HPGe detector were also performed in order to check for impurities.