Neutron/Gamma-Ray Pulse Shape Discrimination with Liquid Scintillation Detectors Based on Average Pulses

In this paper, we present a new pulse shape discrimination (PSD)method that is based on detailed knowledge of the average detectorresponse to radiation. Traditionally, PSD has been performedusing standard methods such as charge integration. In this work,average pulses were obtained for several pulse height regions separatelyfor neutrons and gamma rays. The average neutron andgamma-ray pulses were used in the new PSD algorithm for classificationof a large number of measured pulses. This new PSDapproach proves to be more accurate than the standard chargeintegrationPSD for neutron and gamma rays under 70 keVee(keV electron equivalent; 450 keV neutron energy). Specifically,the improvement is approximately 40 percent for neutrons in thesmallest pulse height bin considered, which was between 23 and30 keVee (corresponding to approximately 175 keV and 225 keVneutron energy, respectively). For this pulse height bin, approximately66 percent of the neutrons were correctly classified. Theaverage number of correctly classified neutrons is approximately82 percent for the average-pulses PSD method between 23 and100 keVee (corresponding to approximately