The optical transmittance and pulse shape discrimination of polystyrene/poly(methyl methacrylate) based plastic scintillators

Polymethyl methacrylate (PMMA) is an optically transparent thermoplastic with favorable processing conditions. In this study, a series of plastic scintillators were prepared via thermal polymerization, and the impact of PMMA content on their transparency and pulse shape discrimination (PSD) ability was investigated. The fabricated samples, comprising a polystyrene (PS)-PMMA matrix, 30 wt% 2,5-diphenyloxazole (PPO), and 0.2 wt% 9,10-diphenylanthracene (DPA), exhibit high transparency with transmissivity ranging from 70.0% to 90.0%(above 415.0 nm) and demonstrate excellent n/γ discrimination capability. The transparency increases with higher PMMA content across the entire visible light spectrum. However, the PSD performance gradually deteriorates as the aromatic matrix is replaced by PMMA. The scintillator containing 20.0 wt% PMMA demonstrates the best stability in terms of PSD properties and relative light yields.