Novel epoxy-bPBD-BisMSB composite plastic scintillator for alpha, beta and gamma radiation detection

Abstract

A composite plastic scintillator is prepared by uniform dispersion of organic fluorophores 2-(4-Biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (b-PBD) and 1,4-bis(2-methylstyryl) benzene (Bis-MSB) in epoxy resin followed by curing at room temperature. The developed scintillator is strong blue emitter (425 nm), confirmed by 365 nm UV excited Photo luminescence and beta particle (90Sr-90Y) excited Radio-luminescence characterizations. The developed scintillator is highly transparent (~ 70%) to emitted light wavelength. Moreover, the scintillator’s blue emission is appropriate for photomultiplier tube (PMT) based scintillation measurement due to its maximum peak spectral response in blue region. Alpha, beta and gamma radiation detection were performed on PMT coupled scintillators of sizes Ø50 mm × 1 mm, Ø50 mm × 5 mm and Ø50 mm × 25 mm respectively. Pulse height spectra were recorded using 1 k Multichannel analyser (MCA) using various reference radiation sources. All scintillators demonstrated promising response to the respective radiations. Absolute detection efficiency of alpha scintillator is obtained as 32% (241Am), 86% of that of standard plastic scintillator EJ-212. Beta endpoint energy and gamma Compton edges showed linear variation w.r.t. corresponding channel numbers. Detection efficiency of beta and gamma scintillator is found to be 35.7% (90Sr-90Y) and 6.7% (136Cs) respectively. The developed scintillator has potential to be used for radioactivity contamination & gamma dose rate measurement applications.