Exploiting fission chain reaction dynamics to image fissile materials
Abstract
Radiation imaging is one potential method to verify nuclear weapons dismantlement. In this work, we present a method to discriminate between non-multiplying and multiplying neutron sources using a neutron coded aperture imaging system. This method applies time-correlated pulse-height (TCPH) analysis to identify neutrons in fission chain reactions and recreate images using only these events. This analysis was applied to measurements of weapons-grade plutonium (WGPu) metal and 252Cf performed at the Nevada National Security Site (NNSS) Device Assembly Facility in July 2015. The results demonstrate it is possible to eliminate the non-fissile 252Cf source from the image while preserving the fissile WGPu source. TCPH analysis was also applied to additional scenes in which the WGPu and 252Cf sources were measured individually. The results of these separate measurements further demonstrate the ability to remove the non-fissile 252Cf source and retain the fissile WGPu source. Simulations performed using MCNPX-PoliMi indicate that in a one hour measurement, hollow WGPu spheres are retained at a 1σ level for neutron multiplications M ≃ 2:7 and above. This work has potential application to dismantlement verification where it may be valuable to verify that all neutron sources in an image are multiplying.
- Authors:
-
- North Carolina State Univ., Raleigh, NC (United States); United States Military Academy, West Point, NY (United States)
- North Carolina State Univ., Raleigh, NC (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Publication Date:
- Research Org.:
- Univ. of Michigan, Ann Arbor, MI (United States)
- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA), Office of Nonproliferation and Verification Research and Development (NA-22)
- OSTI Identifier:
- 1798653
- Grant/Contract Number:
- NA0002534
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment
- Additional Journal Information:
- Journal Volume: 935; Journal ID: ISSN 0168-9002
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; Disarmament verification; Neutron coded aperture imaging; Time-correlated pulse-height analysis
Citation Formats
Chapman, Pete, Mueller, Jonathan, Newby, Jason, and Mattingly, John. Exploiting fission chain reaction dynamics to image fissile materials. United States: N. p., 2019.
Web. doi:10.1016/j.nima.2019.05.001.
Chapman, Pete, Mueller, Jonathan, Newby, Jason, & Mattingly, John. Exploiting fission chain reaction dynamics to image fissile materials. United States. https://doi.org/10.1016/j.nima.2019.05.001
Chapman, Pete, Mueller, Jonathan, Newby, Jason, and Mattingly, John. Tue .
"Exploiting fission chain reaction dynamics to image fissile materials". United States. https://doi.org/10.1016/j.nima.2019.05.001. https://www.osti.gov/servlets/purl/1798653.
@article{osti_1798653,
title = {Exploiting fission chain reaction dynamics to image fissile materials},
author = {Chapman, Pete and Mueller, Jonathan and Newby, Jason and Mattingly, John},
abstractNote = {Radiation imaging is one potential method to verify nuclear weapons dismantlement. In this work, we present a method to discriminate between non-multiplying and multiplying neutron sources using a neutron coded aperture imaging system. This method applies time-correlated pulse-height (TCPH) analysis to identify neutrons in fission chain reactions and recreate images using only these events. This analysis was applied to measurements of weapons-grade plutonium (WGPu) metal and 252Cf performed at the Nevada National Security Site (NNSS) Device Assembly Facility in July 2015. The results demonstrate it is possible to eliminate the non-fissile 252Cf source from the image while preserving the fissile WGPu source. TCPH analysis was also applied to additional scenes in which the WGPu and 252Cf sources were measured individually. The results of these separate measurements further demonstrate the ability to remove the non-fissile 252Cf source and retain the fissile WGPu source. Simulations performed using MCNPX-PoliMi indicate that in a one hour measurement, hollow WGPu spheres are retained at a 1σ level for neutron multiplications M ≃ 2:7 and above. This work has potential application to dismantlement verification where it may be valuable to verify that all neutron sources in an image are multiplying.},
doi = {10.1016/j.nima.2019.05.001},
journal = {Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment},
number = ,
volume = 935,
place = {United States},
year = {Tue May 07 00:00:00 EDT 2019},
month = {Tue May 07 00:00:00 EDT 2019}
}
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