Detectors for the Gamma-Ray Resonant Absorption (GRA) Method of Explosives Detection in Cargo: A Comparative Study

David Vartsky, Mark B. Goldberg, Gideon Engler, Asher Shor, Aharon Goldschmidt, Gennady Feldman, Doron Bar, Itzhak Orion, Lucian Wielopolski

Research output: Contribution to journalConference articlepeer-review

5 Scopus citations


Gamma-Ray Resonant Absorption (GRA) is an automatic-decision radiographic screening technique that combines high radiation penetration with very good sensitivity and specificity to nitrogenous explosives. The method is particularly well-suited to inspection of large, massive objects (since the resonant γ-ray probe is at 9.17 MeV) such as aviation and marine containers, heavy vehicles and railroad cars. Two kinds of γ-ray detectors have been employed to date in GRA systems: 1) Resonant-response nitrogen-rich liquid scintillators and 2) BGO detectors. This paper analyses and compares the response of these detector-types to the resonant radiation, in terms of single-pixel figures of merit. The latter are sensitive not only to detector response, but also to accelerator-beam quality, via the properties of the nuclear reaction that produces the resonant-γ-rays. Generally, resonant detectors give rise to much higher nitrogen-contrast sensitivity in the radiographic image than their non-resonant detector counterparts and furthermore, do not require proton beams of high energy-resolution. By comparison, the non-resonant detectors have higher γ-detection efficiency, but their contrast sensitivity is very sensitive to the quality of the accelerator beam. Implications of these detector/accelerator characteristics for eventual GRA field systems are discussed.

Original languageEnglish
Pages (from-to)243-253
Number of pages11
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 1 Jan 2004
EventHard X-Ray and Gamma-Ray Detector Physics V - San Diego, CA, United States
Duration: 4 Aug 20035 Aug 2003


  • BGO detectors
  • Explosives detection
  • Resonant detectors
  • γ-Ray Nuclear Resonance Absorption (GRA)

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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