Analytical description of pulses measured with an organic liquid scintillator for pulse shape discrimination

In this paper, we present a new pulse shape discrimination (PSD) approach that is based on detailed knowledge of the detector response to given radiation. Traditionally, PSD has been performed using the standard methods such as charge-integration method. Average pulses were obtained for multiple pulse height regions separately for neutrons and gamma rays. The average neutron and gamma-ray pulses were implemented into the new PSD algorithm for classification of a large number of measured pulses. This new PSD approach proves to be more accurate than the standard charge-integration PSD method for low-energy neutron and gamma rays under 90 keVee (keV electron equivalent). The improvement is greater than a factor of two for neutrons in the smallest pulse height bin considered, which was from 26 to 35 keVee. For this pulse height bin, which corresponds to a total energy deposited by the neutron with energy between 200 and 260 keV, approximately 72% of the neutrons were correctly classified. (authors)