Earticle

초록

영어

Background: Radiation portal monitors (RPMs) involving plastic scintillators installed at the border inspection sites can detect illicit trafficking of radioactive sources in cargo containers within seconds. However, RPMs may generate false alarms because of the naturally occurring radioactive materials. To manage these false alarms, we previously suggested an energy-weighted algorithm that emphasizes the Compton-edge area as an outstanding peak. This study intends to evaluate the identification of radioactive sources using an improved energy-weighted algorithm. Materials and Methods: The algorithm was modified by increasing the energy weighting factor, and different peak combinations of the energy-weighted spectra were tested for source identification. A commercialized RPM system was used to measure the energy-weighted spectra. The RPM comprised two large plastic scintillators with dimensions of 174 × 29 × 7 cm3 facing each other at a distance of 4.6 m. In addition, the in-house-fabricated signal processing boards were connected to collect the signal converted into a spectrum. Further, the spectra from eight radioactive sources, including special nuclear materials (SNMs), which were set in motion using a linear motion system (LMS) and a cargo truck, were estimated to identify the source identification rate. Results and Discussion: Each energy-weighted spectrum exhibited a specific peak location, although high statistical fluctuation errors could be observed in the spectrum with the increasing source speed. In particular, 137Cs and 60Co in motion were identified completely (100%) at speeds of 5 and 10 km/hr. Further, SNMs, which trigger the RPM alarm, were identified approximately 80% of the time at both the aforementioned speeds. Conclusion: Using the modified energy-weighted algorithm, several characteristics of the energy weighted spectra could be observed when the used sources were in motion and when the geometric efficiency was low. In particular, the discrimination between 60Co and 40K, which triggers false alarms at the primary inspection sites, can be improved using the proposed algorithm.

목차

ABSTRACT
Introduction
Materials and Method
1. Improvement of Energy-Weighted Algorithm
2. RPM System under Test and Spectrum Measurement Condition
Results and Discussion
1. Spectrum Analysis of Moving Sources
2. Source Identification Test
Conclusion
Conflict of Interest
Acknowledgements
Author Contribution
References

키워드

저자

• Hyun Cheol Lee [ Department of Radiation Convergence Engineering, Yonsei University, Wonju, Korea ]
• Bon Tack Koo [ Department of Radiation Convergence Engineering, Yonsei University, Wonju, Korea ]
• Chang Il Choi [ Korea Institute of Nuclear Safety, Daejeon, Korea ]
• Chang Su Park [ Korea Institute of Nuclear Safety, Daejeon, Korea ]
• Jeongwan Kwon [ Korea Institute of Nuclear Safety, Daejeon, Korea ]
• Hong-Suk Kim [ Korea Institute of Nuclear Safety, Daejeon, Korea ]
• Heejun Chung [ Korea Institute of Nuclear Nonproliferation and Control, Daejeon, Korea ]
• Chul Hee Min [ Department of Radiation Convergence Engineering, Yonsei University, Wonju, Korea ] Corresponding author

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  방사선방어학회지 [Journal of Radiation Protection and Research]

• 간기

  계간

• pISSN

  2508-1888

• 수록기간

  1976~2026

• 등재여부

  KCI 등재,SCOPUS

• 십진분류

  KDC 559 DDC 629