Optimization and Evaluation of PMTs Arrangement in Large Plastic Scintillators for Position-Sensitive Detectors Using Geant4

Kochakpour, Javad; Hosseini, Seyed Abolfazl; Taheri, Ali; Askari, Mojtaba

doi:10.24200/nst.2025.1728.2074

Optimization and Evaluation of PMTs Arrangement in Large Plastic Scintillators for Position-Sensitive Detectors Using Geant4

Articles in Press

Document Type : Research Paper

Authors

javad kochakpour ¹

Seyed Abolfazl Hosseini ²

Ali Taheri ³

Mojtaba Askari ⁴

¹ 1- Department of Energy Engineering, Sharif University of Technology 2- Radiation Applications Research School, Nuclear Science and Technology Research Institute

² Department of Energy Engineering, Sharif University of Technology

³ Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box:14155-1339 Tehran, Iran

⁴ Nuclear science and technology research institute

https://doi.org/10.24200/nst.2025.1728.2074

Abstract

This study focuses on evaluating and optimizing the arrangement of photomultiplier tubes (PMTs) in a plate plastic scintillator detector for applications in position-sensitive detection of radioactive sources. To achieve this, scintillation light processes within the detector were modeled and analyzed using Monte Carlo simulations implemented in the Geant4 toolkit. The research examines three distinct PMT configurations: a central configuration (PMTs placed at the center of each side of the detector), an asymmetric configuration (PMTs arranged unevenly with varying distances across the detector surface), and a corner configuration (PMTs positioned at the corners of the detector). Statistical analysis of the results indicates that the central configuration yields the best performance, with minimal errors: RMSE = 1.51 cm, MAE = 1.26 cm, MRE = 7.03%, and a correlation coefficient R = 0.997. In comparison, the second and third configurations demonstrate reduced accuracy in source localization. These findings suggest that an optimized PMT configuration can significantly enhance the precision and efficiency of detection systems, making them particularly effective for spatially sensitive applications in identifying and localizing radioactive sources.

Keywords

Large Plastic Scintillator

Geant4-toolkit

Position-Sensitive Detector

Scintillation Light Processes

Photomultiplier Tube (PMT)

Main Subjects