Pileup Rejection using Estimation Technique for High Resolution Nuclear Pulse Spectroscopy

High resolution spectroscopy systems need accurate measurement of peak height of pulses. The non-zero response time of the detection system leads to overlapping of pulses, thus affecting the overall performance of the system in terms of throughput, system dead time and energy resolution. In this paper, a new pile up detection technique has been described which is based on estimation of peak height of the pulses. For estimating peak value of the pulses; advantage has been taken of the fact that nuclear pulses have constant shape and same peaking time under no pileup condition. The shape of the pulses are exclusively dependent on shaping circuit and only the amplitude of the pulses will change with respect to the energy associated with individual radiation events. Piled up pulses are detected before the peaking time of the pulses. And piled up condition is detected in real time and also it saves lot of computational time. The method developed is easy to implement using basic analog and digital circuits.