Analysis of three digital n/γ discrimination algorithms for liquid scintillation neutron spectrometry

In mixed neutron/γ radiation fields, particle identification based on different filter algorithms and radiation intensities is an important issue for liquid scintillation neutron spectrometry. We have compared the performance of three algorithms for digital neutron/γ discrimination in a deuterated liquid scintillator. The effects of both digital filters and simulated pile-up events on the performance of these techniques were investigated. The discrimination methods utilized are the digital charge comparison (CC) method, simplified digital charge collection (SDCC) method and pulse gradient analysis (PGA) method. The results show that the SDCC and the CC methods are preferred choices when applied in low count-rates fields, whereas PGA method with a seven-point average running filter is favorable when pile-up signals constitute a large fraction of the detected events. All these discrimination approaches are potentially suitable for developing a compact digital neutron spectrometer in mixed neutron/γ radiation fields for use in various applications.

► We describe three digital n/γ discrimination algorithms.
► Effects of both digital filters and simulated pile-up events were studied.
► The CC and SDCC algorithms are preferred in low count-rates fields.
► The PGA algorithm with a digital filter is favorable in high count-rates fields.