A general method for optimizing the parameter of α/β discrimination in liquid scintillation counting

Abstract

In the application of liquid scintillation counting (LSC), the α/β discrimination is carried out with the function of pulse shape analysis (PSA), which requires the setting of the optimum PSA level. The optimum PSA is usually determined by the generation of cross-over plots (referred as Conventional Method), whereby a pair of pure α and β emitters is essential. However, in some cases, a pure α or β emitter is not available. In order to deal with this problem, we have developed a new approach (referred as Present Method) to set the optimum PSA by measuring the sample itself of mixed α/β emitters. The results from Present Method are in good agreement with those from Conventional Method when a pair of pure α and β emitters is available. Besides the obvious advantage that Present Method can be applied no matter whether a pure α emitter or a pure β emitter is available or not, Present Method has another important advantage that it is not necessary to prepare the quench curves for the measurement of samples with different quench levels. Therefore, Present Method is a general method for optimizing the parameter of α/β discrimination in LSC. In addition, the application of Present Method can be broadened by combining the method with α spectrometry.