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Alternative Signature Detectors for Long Range Nuclear Material Identification



TECHNOLOGY AREA(S): Nuclear Technology, Sensors

OBJECTIVE: To develop a method for identifying nuclear materials at distances over 100m through the detection of alternative signatures.

DESCRIPTION: Current technology can reliably identify radioactive materials at close range (<50m) through the detection of ionizing decay products (beta, gamma, neutron). However, detecting many nuclear materials (e.g. Pu, HEU) with conventional detectors at distances over a few meters is difficult due to shielding, geometric considerations, and the inherent long half-lives of the radionuclides. New research has shown the potential to detect these materials through alternative signatures. In particular, gamma and neutron radiation creates a unique ionization signature in the surrounding air that can be used to detect the presence of radioactive material. This topic seeks proposals to exploit these alternative signatures to detect Special Nuclear Materials (SNM) at distances over 100m, far greater than current detection limits. Although detecting other mid-mass isotopes may also be of interest (60Co, 137Cs), this study should focus on fissile isotopes: 239Pu and 235U. Designs should demonstrate sensitivity to radioactive sources equivalent to strategic SNM levels: 5kg 235U or 2kg Pu. The total detection time should be on the order of a few minutes. This topic will not address methods of active interrogation using ionizing radiation.

PHASE I: A trade study should be conducted to assess the best detection method using alternative signatures. The study should address the signal size produced by critical quantities of SNM and demonstrate sensitivity to these signals from >100m. A proof of principle experiment should be carried out to demonstrate the chosen detection method’s viability.

PHASE II: Phase II projects should develop a prototype device. Although not necessarily hand-held, the prototype should be man-portable and capable of being used in a field test. The device should demonstrate the detection of radionuclides from >100m standoff distances.

PHASE III DUAL USE APPLICATIONS: PHASE III: Based on successful Phase II results, the final product design should focus on minimizing device form factor and increasing ruggedness for use in the field. DUAL USE APPLICATIONS: In addition to SNM detection for national security purposes, this technology could also be used for environmental monitoring.


  • Kumarasiri Konthasinghe, Kristin Fitzmorris, Manoj Peiris, Adam J. Hopkins, Benjamin Petrak, Dennis K. Killinger, and Andreas Muller. "Laser-Induced Fluorescence from N2+ Ions Generated by a Corona Discharge in Ambient Air." Appl. Spectrosc. 69, 1042-1046 (2015)
  • Erin T. McCole Dlugosz, Reginald Fisher, Aleksey Filin, Dmitri A. Romanov, Johanan H. Odhner, and Robert J. Levis. “Filament-Assisted Impulsive Raman Spectroscopy of Ozone and Nitrogen Oxides.” The Journal of Physical Chemistry A 2015 119 (35), 9272-9280 DOI: 10.1021/acs.jpca.5b06319

KEYWORDS: Alternative Signatures, Standoff Detection, Nuclear Detection, SNM


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