Measurement of Disintegration Rates and Absolute γ‐ray Intensities

The majority of practical radioactive materials decay by modes that include γ‐ray emission. For questions of “how much” or “how pure,” one must know the absolute intensities of the major radiations. We are using liquid scintillation counting (LSC) to measurements of disintegration rates, coupled with γ‐ray spectroscopy to measure absolute γ‐ray emission probabilities. Described is a study of the 227Th chain yielding absolute γ‐ray intensities with ∼0.5% accuracy and information on LSC efficiencies.