Abstract
Transmission radiography using megaelectronvolt radiation is a powerful nondestructive method for determining elemental composition. Radiography is typically performed with either neutrons or photons, but neither of these probes is universally applicable. We experimentally demonstrate that a significant increase in the contrast for small elemental variations in object composition can be realized by combining the multiple-monoenergetic-neutron and multiple-monoenergetic-photon transmission radiography techniques. The multimodal source is based on deuteron-driven low-energy nuclear reactions that produce both neutrons and photons at discrete energies. The neutron time-of-flight technique is used to measure the transmission over a broad range of neutron energies and is combined with spectroscopic photon transmission radiography. This work demonstrates the use of a single, multiparticle, multiple-monoenergetic-radiation source and a single type of radiation detector to simultaneously perform neutron and photon spectroscopic radiography. Four different material-identification metrics are used, which show a factor-of-3-or-greater increase in sensitivity to changes in material composition when compared with traditional dual-energy photon radiography, and are in agreement with simulations that establish a direct correspondence to known photon and neutron interaction cross sections. Furthermore, the ability to infer the presence of objects consisting of impure elements, layers of different elements, or non-natural isotope concentrations is demonstrated.
Original language | English |
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Article number | 044085 |
Journal | Physical Review Applied |
Volume | 11 |
Issue number | 4 |
DOIs | |
State | Published - Apr 26 2019 |
Funding
This work was supported by the U.S. Department of Homeland Security (Grants No. 2014-DN-077-ARI078-02 and No. 2015-DN-077-ARI096). The research of J.N. was performed under appointment to the Nuclear Nonproliferation International Safeguards Fellowship Program sponsored by the National Nuclear Security Administration’s Office of International Safeguards (Grant No. NA-241).