Fabrication and Characterization of Epoxy Resin Co-doped with 2,5-Diphenyloxazole and Cerium Fluoride Nanoparticles for Radiation Detection

This paper presents the fabrication and characterization of a plastic scintillator prepared from epoxy resin doped with 2,5-diphenyloxazole (PPO) and cerium fluoride nanoparticles (CeF3 NPs) for radiation detection. The CeF3 NPs were prepared by a chemical process and examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM); it was found that the prepared particles were true CeF3 NPs with an average particle size of approximately 17 nm. The CeF3 NPs were co-doped with PPO into epoxy resin and formed into a plastic scintillator of 3 cm in diameter and 2 cm in length. Analysis of the scintillator's luminescence properties using a fluorescence spectrometer revealed that excitation at 300 nm resulted in maximum emission at 366 nm. Scintillation response testing, conducted by coupling the plastic scintillator to a photomultiplier tube, demonstrated successful radiation detection capabilities. The optimal sample preparation conditions were determined to be 0.4% by weight of PPO doping and 0.2% by weight of CeF3 NPs co-doping, which yielded the best gamma-ray detection performance. Energy response testing using radiation sources Na-22, Cs-137, Mn-54, and Co-60 showed that the relationship between incident gamma-ray energy and the signal measured by the multichannel analyzer exhibited 99.83% linearity. For measuring gamma rays at 662 keV, the fabricated plastic scintillator showed a light yield of 1,810 photons/MeV, corresponding to 39% of that of a commercial plastic scintillator (4,640 photons/MeV). The fabricated plastic scintillators were also responsive to X-rays and alpha particles; namely, when excited with X-rays, they exhibited a scintillation efficiency equal to 15% of that of the reference BGO crystal, and when excited with 5.5 MeV alpha particles from Pu-238, they showed an energy resolution of 48.27%.