An optimization of energy window settings for positron annihilation lifetime spectrometers

An optimization of energy window settings for a positron annihilation lifetime spectrometer is necessary for high performance. A spectrometer employing the fast-fast coincidence technique with a pair of plastic scintillation detectors was used in this study. In the present spectrometer, the data are acquired in event-by-event list mode with a multi-parameter acquisition system. A fuzzy approach is applied for determination of the optimal values of the energy windows using the minimum-type and product-type fuzzy decisions. The performance of the used spectrometer is obviously improved with the optimal widths of the energy windows of both start and stop γ-rays.