Characterization of EJ-250, Li-loaded plastic scintillator for simultaneous discrimination of gamma rays, slow and fast neutrons

Abstract In this work, the pulse shape discrimination (PSD) capability for gamma rays as well as fast and thermal neutrons of EJ-250 lithium-loaded plastic scintillator is investigated and compared with that of EJ-270 lithium-loaded plastic scintillator and EJ-309B5 boron-doped liquid scintillator. Measurements were performed in a mixed neutron-gamma radiation field generated by an intense PuBe source (∼ 10 6 neutrons·s -1 · 4 π -1). To enhance the detection efficiency for thermal and epithermal neutrons, the neutron source was embedded in an 18 cm diameter paraffin moderator.The study addresses neutron-gamma discrimination performance, photoelectron yield, and detailed analysis of scintillation pulse shapes associated with gamma rays, thermal neutrons, and fast neutrons. Pulse shape analysis was employed to provide deeper insight into the detector response mechanisms to different types of radiation interactions and their impact on signal separation efficiency in a mixed radiation field. The results show that while all investigated scintillators exhibit pulse shape discrimination capability, the EJ-250 scintillator offers the most promising overall performance as a homogeneous detector for simultaneous discrimination of gamma rays, fast neutrons, and thermal neutrons.