Neutron stimulated gamma ray measurements for chlorine detection

Authors: Kavetskiy, Aleksandr; Yakubova, Galina; SARGSYAN, NIKOLAY - Auburn University; Prior, Stephen - Steve; Torbert, Henry - Allen

Submitted to: Inst of Electrical and Electronic Engineers Transactions of Nuclear Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/2021
Publication Date: 6/4/2021
Citation: Kavetskiy, A.G., Yakubova, G.N., Sargsyan, N., Prior, S.A., Torbert III, H.A. 2021. Neutron stimulated gamma ray measurements for chlorine detection. Inst of Electrical and Electronic Engineers Transactions of Nuclear Science. 68(7):1495-1504. https://doi.org/10.1109/TNS.2021.3086327.
DOI: https://doi.org/10.1109/TNS.2021.3086327

Interpretive Summary: This project examined different methods of neutron-gamma technology as alternative means of measuring chlorine in solid objects and water solutions, and soil contaminated areas. The preferred method was demonstrated to be Pulsed Fast Thermal Neutron Analysis (PFTNA). Paired with GPS, a chlorine field map was created that accurately identified actual position and size of chlorine contaminated locations. Measurement of marine water salinity and disclosure of chlorine contaminated soil areas are promising directions for the further development and application of the PFTNA method.

Technical Abstract: Application of neutron-gamma analysis for chlorine determination in different materials (e.g., solids, aqueous solutions, surface contaminations) are discussed. Solid samples were measured with a Pulsed Fast Thermal Neutron Analysis (PFTNA) system consisting of a pulsed neutron generator and sodium iodide gamma detectors and an Associated Particle Imaging (API) system consisting of a neutron generator (with a built-in alpha detector) and sodium iodide gamma detector; all sample measurements were made under similar conditions (neutron flux values, detector side area for crossing gamma flux). Advantages of PFTNA over the API method were demonstrated based on comparison of metrological parameters (i.e., minimal detectible level for a1h measurement period and clock time required to reach 5% measurement accuracy). For these reasons, the PFTNA system in scanning mode effectively identified areas of artificial chlorine contamination in the field. Paired with GPS, a chlorine contamination map was created from PFTNA scanning results; this map accurately identified actual position and size of chlorine contaminated locations in the field. Chlorine contaminated areas of ~4.5 m2 were effectively located within the ~500 m2 field during a ~2h scanning period. Based on results from this work, promising directions for further application of the PFTNA method are measurements of marine water salinity and disclosure of chlorine contamination in soil.