Design and Fabrication of PS-PMMA-Based Plastic Scintillators with Bis(pinacolato)diboron Loading for n/γ Pulse-Shape Discrimination

Efficient discrimination of thermal neutrons, fast neutrons, and γ-rays is of great importance for radiation monitoring, nuclear security, and fundamental research. However, conventional plastic scintillators, despite their low cost and fast response, generally suffer from limited neutron/gamma (n/γ) discrimination capability, which motivates the development of advanced scintillation materials and dedicated detection systems. In this work, we developed a polystyrene/poly(methyl methacrylate) (PS/PMMA) blended plastic scintillator that combines the high light yield of PS with the mechanical robustness of PMMA. A boron-containing dopant, bis(pinacolato)diboron (B2Pin2), was introduced together with optimized dye and cross-linker concentrations to enhance neutron sensitivity and overall scintillation performance. To evaluate the detector performance, we further constructed a custom measurement platform consisting of a photomultiplier tube (PMT)-based readout module and a high-speed pulse waveform analysis system. Experiments with a 241Am–Be source demonstrate that the developed scintillator exhibits effective pulse shape discrimination capability, demonstrating statistical discrimination of γ-ray-, fast-neutron-, and thermal-neutron-related event populations within a single detector system.