Green emitting plastic scintillator with neutron/gamma pulse shape discrimination for fast neutron detection

In this report, high concentrations of dye doped advanced plastic scintillators are fabricated by bulk thermal polymerization. High soluble primary fluor 2,5-diphenyloxazole (PPO) having emission wavelength within the UV spectrum and the wavelength shifter 3-hydroxyflavone (3HF) showing emission peak at 530 nm were mixed into the styrene base matrix. The wavelength shifter eliminates the phenomenon of self-absorption, which increases the energy transfer efficiency from the primary dye to the spectral shifter. The structural confirmation was performed by XRD measurement and the surface morphology of the synthesized polystyrene-based plastic scintillators were examined using FESEM. The elemental analysis, purity of the material, chemical states and its compositions were analyzed through EDS, FT-Raman and XPS techniques, respectively. Our studies revealed the good scintillation performance of these novel clear and transparent scintillators for fast neutron detection, showing maximum emission peak around 540 nm with bright green fluorescence, fast scintillation decay under neutron and gamma excitation and good neutron/gamma pulse shape discrimination with a figure of merit of 1.6. The fabricated plastic scintillators possessed an energy linearity of more than 99.8% from the pulse spectra analysis.

Automated summary

High concentrations of dye doped advanced plastic scintillators were fabricated using bulk thermal polymerization. The addition of a wavelength shifter improved the energy transfer efficiency and eliminated self-absorption. The synthesized plastic scintillators exhibited good scintillation performance for fast neutron detection with high energy linearity.