Neutron-Gamma Discrimination Comparison of Three Organic Scintillators with CFD-based Pulse Shape Discrimination Method

In this work, we compare the pulse shape discrimination (PSD) capabilities of three organic scintillators. Accurate PSD relies on the optimization of pulse processing parameters. For example, in charge integration based PSD, the results depend heavily on the choices of the pulse gates. The PSD method that developed here to improve the traditional charge integration method by using constant fraction discrimination (CFD) on the tail of each pulse to find the best integration settings. The advantage of this approach is that optimization is not needed to find the gate time and only the detector response to gamma rays is needed to find optimal PSD parameters. The organic scintillators compared in this paper are a) the recently-developed deuterated trans-stilbene (stilbene-d
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), b) the EJ-309 liquid scintillator, and c) the small-molecule organic glass scintillator. The three detectors are used to measure a
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Cf neutron source and calculated the figure-of-merit to evaluate the PSD performance. The result demonstrates that the method is robust and applies regardless of the detector type. The stilbene-d
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outperforms the other two detectors in terms of PSD ability, for a given light output range, and therefore, it is most suitable for neutron/gamma discrimination applications.