Effects of delaying measurements of concentration using neutron activation analysis on explosive taggants. (February 2020)

• Record Type: Journal Article
• Authors: Seman, James; Castano Giraldo, Carlos Henry; Johnson, Catherine E.
• Is Part Of: Applied radiation and isotopes. Volume 156(2020:Feb.)
• Publication Date: 2020-02
• Subjects: Radiology -- Periodicals; Radiation -- Industrial applications -- Periodicals; Nuclear chemistry -- Periodicals; Internet resource; Periodical; 660.298
• DOI: 10.1016/j.apradiso.2019.109007
• Languages: English
• ISSNs: 0969-8043

Abstract

Abstract: A nuclear barcode has been proposed to identify taggants added to explosives, which encodes identifying information by adding a unique combination of taggant elements at different concentration levels. Testing was conducted on two single element solutions at three concentrations to determine minimum detection concentration levels. The effect of delaying the time to obtain measurements and its effect on uncertainty over approximately four half-lives (5 days) was tested on five 1 part per million holmium solutions. Highlights: NAA was used to detect rare earth elements in post blast residues. NAA is sensitive up to the ppb range and is not affected by detonation. Immediate measurements had uncertainties up to 38% lower than after 2.5 half-lives. Holmium should be measured within 67 h of irradiation (2.5 half-lives). Optimum holmium measurement would be around 27 h after activation (approximately 1 half-life).