Optimization of Plastic Scintillator for Detection of Gamma-Rays: Simulation and Experimental Study

Sujung Min,Sangbum Hong,Kwang-Hoon Ko,Youngsu Kim,Changhyun Roh,Bumkyung Seo,Jaehak Cheong

doi:10.3390/chemosensors9090239

Abstract

Plastic scintillators are widely used in various radiation measurement applications, and the use of plastic scintillators for nuclear applications including decommissioning, such as gamma-ray detection and measurement, is an important concern. With regard to efficient and effective gamma-ray detection, the optimization for thickness of plastic scintillator is strongly needed. Here, we elucidate optimization of the thickness of high-performance plastic scintillator using high atomic number material. Moreover, the EJ-200 of commercial plastic scintillators with the same thickness was compared. Two computational simulation codes (MCNP, GEANT4) were used for thickness optimization and were compared with experimental results to verify data obtained by computational simulation. From the obtained results, it was confirmed that the difference in total counts was less than 10% in the thickness of the scintillator of 50 mm or more, which means optimized thickness for high efficiency gamma-ray detection such as radioactive 137Cs and 60CO. Finally, simulated results, along with experimental data, were discussed in this study. The results of this study can be used as basic data for optimizing the thickness of plastic scintillators using high atomic number elements for radiation detection and monitoring.

Highlights

Published: 25 August 2021Since the plastic scintillator was first developed by Schorr and Torne in 1950 [1], it has been widely used in nuclear physics, high energy physics fields, and industrial fields such as thickness and density measurement
CdS/ZnS quantum dots of high atomic number were added to a styrene-based plastic scintillator, and a scintillator with a diameter of 50 mm, thickness of 30 mm, and 50 mm was fabricated through a thermal polymerization process
Two computational simulation codes were used to optimize the thickness of the CdS/ZnS-loaded plastic scintillator

Summary

Introduction

Since the plastic scintillator was first developed by Schorr and Torne in 1950 [1], it has been widely used in nuclear physics, high energy physics fields, and industrial fields such as thickness and density measurement. “Aromatic substituted oxazole” is a long-chain structure composed of simple aromatic rings, and these materials are dissolved in an organic solvent, and various types of compounds have been successfully demonstrated in liquid and plastic scintillators [3,4]. A unique characteristic of zero-dimensional semiconductor crystals called quantum dots is that it is possible to control the carrier confinement effect and the band gap (eV). CdS is one of the II–VI semiconductors and has a bandgap of about 2.42 eV Research on the development of high-efficiency plastic detectors sensitive to radiation by adding a high atomic number material to a plastic matrix has been conducted [5].

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Conclusion