INVESTIGATING THE CHARACTERISTICS OF LARGE-VOLUME PVT SCINTILLATION DETECTORS IN THE RADIATION PORTAL MONITORS USING MONTE CARLO SIMULATIONS
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https://doi.org/10.54939/1859-1043.j.mst.75A.2021.52-59Keywords:
Radiation portal monitors (RPMs); Scintillation detectors; Monte Carlo simulation method.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.
References
[1]. Runkle, Robert C., et al. "Analysis of spectroscopic radiation portal monitor data using principal components analysis." IEEE Transactions on Nuclear Science 53.3 (2006): 1418-1423.
[2]. Nafee, Sherif S., et al. "A theoretical approach to calibrate radiation portal monitor (RPM) systems." Applied Radiation and Isotopes 66.10 (2008): 1474-1477.
[3]. Gagnon, Jean‐Christophe, et al. "Dosimetric performance and array assessment of plastic scintillation detectors for stereotactic radiosurgery quality assurance." Medical physics 39.1 (2012): 429-436.
[4]. Mooney, Christopher Z. “Monte carlo simulation”. No. 116. Sage, 1997.
