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

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(NO 3 ) 2 ), a high-Z material, into a photocurable resin. The Pb(NO 3 ) 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(NO 3 ) 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(NO 3 ) 2 exhibited a gamma-ray counting efficiency for a 137 Cs 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(NO 3 ) 2 and DMSO, the 5 wt% Pb(NO 3 ) 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.