Fabrication and characterization of uniformly dispersed Pb(NO3)2-loaded 3D-printed plastic scintillators with enhanced gamma-ray detection capabilities

Abstract

Plastic scintillators inherently suffer from the limitation of low gamma-ray counting efficiency due to their low atomic number (Z). To address this, this study explored the incorporation of lead (II) nitrate (Pb(NO3)2), a high-Z material, into a photocurable resin. The Pb(NO3)2-loaded plastic scintillators were fabricated using Digital Light Processing (DLP) type 3D printing, wherein dimethyl sulfoxide (DMSO) was employed as a co-solvent to ensure uniform dispersion of the Pb(NO3)2 within the polymer matrix. This uniform dispersion was confirmed by Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS) analysis of the scintillator's cutting surface. The evaluation of scintillation properties showed that the scintillator loaded with 5 wt% of Pb(NO3)2 exhibited a gamma-ray counting efficiency for a137Cs source that was 1.64 times higher than that of the commercial plastic scintillator, BC408. Although the optical transmittance decreased due to the addition of Pb(NO3)2 and DMSO, the 5 wt% Pb(NO3)2 sample maintained a relative light output of 55.51% compared to BC408. Additionally, the fast timing characteristics were preserved, with the loaded scintillators exhibiting a decay time of 3.23–3.41 ns, nearly identical to that of the unloaded sample.