Comparative Study between Self-Developed Plastic Scintillators and EJ-276D

[Background] As one of important neutron-sensitive scintillators, plastic scintillator has been widely used in applications such as non-destructive testing, reactor monitoring, and nuclear physics. [Purpose] This study aims to conduct comparative performance tests between the Ø2.54 cm×2.54 cm and Ø5.08 cm×5.08 cm self-developed plastic scintillators (SD-PS) and EJ-276D. [Methods] A testing platform was established using photomultiplier tube (PMT) and a high-speed digitizer to comparatively evaluate the radiation response performance of Ø2.54 cm×2.54 cm and Ø5.08 cm×5.08 cm self-developed right cylindrical plastic scintillators with two different formulations, alongside EJ-276D scintillators of corresponding sizes. Energy calibration was performed for each scintillator using a 137Cs source to determine the relative light output, confirming that the reproducibility from test method was less than 5%. A 252Cf fission ionization chamber was employed to assess the neutron-gamma discrimination capability of the four plastic scintillators, and each scintillator was also utilized to measure the neutron-gamma time-of-flight spectrum of the 252Cf source, from which the Figure of Merit (FoM), relative detection efficiency, timing accuracy, and gamma misidentification were derived. [Results] The results indicate that the light yield of the Ø2.54 cm×2.54 cm self-developed plastic scintillator is comparable to that of the corresponding EJ-276D, with the Figure of Merit less by up to 10% in the 60-640 keVee energy range and detection efficiency less by 19%. The Ø5.08 cm×5.08 cm self-developed scintillator shows a 15% lower light yield compared to the corresponding EJ-276D, with the FoM less by up to 26% and detection efficiency less by 25% over the same energy range. The timing accuracy of the Ø2.54 cm×2.54 cm and Ø5.08 cm×5.08 cm self-developed scintillators are 0.87 ns and 1.25 ns, respectively, which are superior to those of the EJ-276D (1.00 ns and 1.38 ns). For all scintillators, the gamma misidentification rate remained less than 1% at an energy threshold of 120 keVee. [Conclusions] The test results indicate that the radiation detection performance of the Ø2.54 cm×2.54 cm self-developed plastic scintillator is comparable to that of EJ-276D.