Comparative Evaluation of Polystyrene-based Plastic Scintillator for Gamma Detection

Abstract

The objective of this study is to provide useful information for the fabrication of large plastic scintillators that can be utilized in radiation portal monitors (RPMs). A plastic scintillator was fabricated using the injection method, with polystyrene (PS) as the matrix, and para-terphenyl (PTP) and 1,4-bis [2- (phenyloxazolyl)] - benzene (POPOP) as primary and secondary dopants, respectively. The scintillator was characterized based on its absorption spectrum, emission spectrum, and gamma radiation spectrum. The absorption spectrum evaluation using a spectrophotometer UV-Vis revealed that PS absorbs photons at a wavelength of 310 – 340 nm. The emission spectrum evaluation showed that PS containing POPOP exhibited a maximum emission at a wavelength of 421 nm. The evaluation of cesium 137 (¹³⁷Cs) and cobalt 60 (⁶⁰Co) gamma spectrum using the photomultiplier tube (PMT) Hamamatsu R878 showed that the scintillator exhibited Compton spectrum characteristics, with a gross counting maximum of 0.78 and 0.89, respectively, compared to a commercial plastic scintillator.