Hybrid method for digital pulse shape discrimination in organic scintillation detectors

Abstract

Digital signal processing (DSP) simplifies the implementation of pulse shape discrimination (PSD) methods in a cost-effective manner, no matter how complicated they are complicated. This paper deals with the development of a new concept in DSP for PSD, meaning to combine several basis PSD features and obtain a hybrid factor, deeming to inherit benefits of its basis methods. In this regard, we will consider the neutron-gamma discrimination problem, by appropriately combining different PSD methods, namely the Charge Integration Method (CIM), the Zero-Crossing Method (ZCM) and the so-called Simplified Charge Collection Method (SCCM) among several possibilities. It is revealed that the hybrid method should be fed by independent basis PSD factors, keeping in mind that different PSD methods might not be truly uncorrelated. Here, the proposed hybrid PSD factors (via combining CIM-ZCM-SCCM) were implemented. A quantitative analysis of the results, shows that this hybridization concept is generally able to improve the discrimination quality, increasing the FoM over the studied dynamic range. The proposed hybrid formula is simply based on a multiplication of individual PSD factors, but one may define more complex hybrid features in this framework, aiming to improve existing PSD methods by combining them.