Cosmic-Ray-Induced Ship-Effect Neutron Measurements and Implications for Cargo Scanning at Borders

Journal Article · Tue Mar 11 00:00:00 EDT 2008 · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, 587(1):89-100

DOI:https://doi.org/10.1016/j.nima.2007.12.031· OSTI ID:937371

Kouzes, Richard T; Ely, James H; Seifert, Allen; Siciliano, Edward R; Weier, Dennis R; Windsor, Lindsay K; Woodring, Mitchell L; Borgardt, James D; Buckley, Elise D; Flumerfelt, Eric L; Oliveri, Anna F; Salvitti, Matthew

Neutron measurements are used as part of the interdiction process for illicit nuclear materials at border crossings. Even though the natural neutron background is small, its variation can impact the sensitivity of detection systems. The natural background of neutrons that is observed in monitoring instruments arises almost entirely from cosmic ray induced cascades in the atmosphere and the surrounding environment. One significant source of variation in the observed neutron background is produced by the “ship effect” in large quantities of cargo that transit past detection instruments. This paper reports on results from measurements with typical monitoring equipment of ship effect neutrons in various materials. One new result is the “neutron shadow shielding” effect seen with some low neutron density materials.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 937371
• Report Number(s): PNNL-SA-57381
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, 587(1):89-100, Journal Name: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, 587(1):89-100
• Country of Publication: United States
• Language: English