New ultrafast low-cost polyurethane based plastic scintillator

The study of plastic scintillators with polyurethane (PU) matrix based on cycloaliphatic isocyanate 4,4 & PRIME;-methylenebis (cyclohexyl isocyanate) (H12MDI) and 2,5-diphenyloxazole (PPO) as a luminescence activator is presented. A number of samples with different PPO content amounting up to 20 wt% were synthesized and their optical and luminescence characteristics were investigated. Pure H12MDI - PU based polymer exhibits low optical density in the spectral region 350-500 nm characteristic of the PPO emission band. The PU sample loaded with 5 wt% PPO demonstrated a light yield of 1088 photons/MeV and ultrafast rise and decay time of few picoseconds and few nanoseconds, respectively. The estimated coincidence time resolution (CTR) value for a PU sample is 1.4 times smaller than that known for a commercial scintillator BC-422 available for ultrafast timing applications.