He jishu (Nov 2021)
Parameter optimization and pile-up identification of cusp shaping for nuclear pulse signal
Abstract
BackgroundCusp shaping of nuclear pulse signal is widely used in shaping and amplitude extraction of nuclear pulse signal (NPS) because of its optimal signal-to-noise ratio, high counting rate and strong compatibility.PurposeThis study aims to achieve the parameter optimization and pile-up identification of cusp shaping for NPS.MethodsFirst of all, based on the finite width cusp shaping algorithm, the shaping process was deduced for the cusp shaping of the simulated nuclear signal and the actual nuclear signal respectively. The optimal selection of attenuation coefficient and shaping width was investigated by least square fitting. According to the characteristics of cusp shaping, a stack recognition algorithm was designed to achieve cusp shaping, pile-up identification and separation, amplitude extraction of nuclear pulse signal. Then, the output signal of NaI detector was taken for performance comparison of three processing methods of pulse signal direct shaping, pile-up rejection, pile-up identification and separation of pile-up nuclear signal, hence the optimized parameters were obtained. Finally, the characteristic X-ray energy spectrum of Fe (Si PIN detector) was experimentally tested by cusp shaping with optimized parameters.ResultsThe results show that the cusp shaping output pulse amplitude has an exponential relationship with the shaping width, and the peak position of the nuclear pulse signal is in linear relationship with the peak position of the cusp shaping output pulse. Experimental test results show the cusp shaping has better counting rate and good application prospect under the condition of equal energy resolution.ConclusionThe pile-up identification algorithm can effectively realize the cusp shaping, pile-up identification and separation, as well as the amplitude extraction of the nuclear pulse signal.
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