Measurement of Radioactive Disintegration Rate by the Coincidence Method

The principles of radioactive disintegration rate measurement by the coincidence method are reviewed. It is shown that the basic equations for complex decay can be translated into formulae suitable for deducing absolute rates from observed counting data without requiring any knowledge of the decay scheme constants. The formulae are generally valid for β–γ emitters under conditions attainable in practical 4πβ–γ coincidence systems. Currently used techniques and various factors which influence the accuracy of measurement are discussed.