Gross alpha and beta indices in water samples revisited

Gross α and β indices for water samples are generally determined simultaneously when a gas-flow proportional counter is used. The thickness of the source and the α-particle energy are factors of great importance due to self-absorption or energy loss effects. Two variables have been studied: the use of different salts to produce standards with several thicknesses and the use of different radionuclides for the calibration process. Samples of known activity were prepared and measured for checking the procedures.