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Comparison of MCNP and experimental measurements for an HPGe-based spectroscopy portal monitor

  • Application of Nuclear Techniques to National Security and Treaty Monitoring
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Abstract

The necessity to monitor international commercial transportation for illicit nuclear materials resulted in the installation of many nuclear radiation detection systems in Portal Monitors. To overcome the difficulty of innocent alarms due to a large content of natural radioactivity or medical nuclides, Department of Homeland Security (DHS) supported the writing of the ANSI N42.38 standard (Performance Criteria for Spectroscopy-Based Portal Monitors used for Homeland Security) to define the performance of a portal monitor with nuclide identification capabilities, called a Spectroscopy Portal Monitor. To accomplish the necessary performance, several different HPGe detector configurations were modeled using MCNP for the horizontal field of view (FOV) and vertical linearity of response over the detection zone of 5 meters by 4.5 meters for 661 keV as representative of the expected nuclides of interest. The configuration with the best result was built and tested. The results for the FOV as a function of energy and the linearity show good agreement with the model and performance exceeding the requirements of N42.38.

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Correspondence to R. M. Keyser.

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Keyser, R.M., Hensley, W., Twomey, T.R. et al. Comparison of MCNP and experimental measurements for an HPGe-based spectroscopy portal monitor. J Radioanal Nucl Chem 276, 399–405 (2008). https://doi.org/10.1007/s10967-008-0518-9

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  • DOI: https://doi.org/10.1007/s10967-008-0518-9

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