Effect of high Z materials loading in the performance of polystyrene-based thin-film plastic scintillators

Abstract

The paper describes the effect of high effective atomic number (Zeff) materials loading in polystyrene based thin-film Plastic Scintillators (PS). Thin plastic scintillator sheets have been loaded with high Z materials such as BaFBr:Eu, Gd2O2S:Tb, Gd2O3, BaF2, CeO2 and Bi2O3. Polystyrene based PS sheets of 250 ± 50 μm thickness have been prepared by dissolving predetermined quantities of polystyrene, 2,5-Diphenyloxazole (PPO) and 1,4-bis(5-phenyl-2-oxazolyl) benzene (POPOP) in the p-xylene solvent. High Zeff material powders of 23μm size are mixed in the plastic scintillator solution and coated over the cellulose acetate-based transparency sheets. The dried films are peeled off, and their photoluminescence, radioluminescence, pulse height spectrum and response to alpha, beta, gamma and neutron radiations are studied by adopting suitable methods. The high Zeff materials for loading in PS are selected based on their physical properties like refractive index, bandgap, Zeff, Photoluminescence (PL) properties. While the composite scintillator loaded with 14.3 wt% of BaFBr:Eu2+ showed significant increase compare to other high Z materials. The loading concentration has been optimized as 14.3 wt% from the BaFBr:Eu2+ studies. Most of the composite scintillators showed improvement in radioluminescence and pulse height spectra for different radiations.