Investigating the Characteristics of Large-Volume PVT Scintillation Detectors in the Radiation Portal Monitors Using Monte Carlo Simulations

Abstract

This paper presents the characteristics determination process of the large-size Polyvinyl Toluene (PVT) scintillation detectors using MCNP5 simulation code. The energy spectra using a 137Cs calibration source, absolute efficiency in the energy range of 50 ÷ 3000 keV, and the angular response of the EJ-200 50×50×5 cm3 and 25×25×5cm3 are investigated. The simulated energy spectra are in good agreement with the experimental spectra. The results of determining the absolute efficiency show that the EJ-200 50×50×5 cm3 and 25×25×5cm3 plastic detectors have detection efficiencies of 16,3% and 9,2%, respectively, at 10cm source-to-detector distance, and down to 0,6% and 0,17% at 100 cm source-to-detector distance. The angular responses of the detectors show that the detection efficiency value reached ≥ 90% of the maximum value with the incident angle less than 5π/6. The results can be applied in the process of design optimization of plastic-based radiation portal monitors.

Effect of Photomultiplier Tube Voltage on the Performance of Sealed NaI (Tl) Scintillator Detectors

“…In order to ascertain the accuracy of the experimental data, an advanced and highly sophisticated software tool known as the MCNP5 program was employed to simulate the intricate process of photon transport [15,16]. Trough this rigorous simulation process, the MCNP5 program was used to describe this complex process, which provided a valuable benchmark for comparing and evaluating the experimental fndings [17][18][19][20].…”