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Engineering Commons

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Nuclear Engineering

Air Force Institute of Technology

Theses and Dissertations

Nuclear data covariance

Publication Year

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Full-Text Articles in Engineering

Neutron Energy Tuning Assemblies For Nuclear Weapon Environment Applications At The National Ignition Facility, Nicholas J. Quartemont Sep 2021

Neutron Energy Tuning Assemblies For Nuclear Weapon Environment Applications At The National Ignition Facility, Nicholas J. Quartemont

Theses and Dissertations

An energy tuning assembly was developed to spectrally shape the National Ignition Facility deuterium-tritium fusion neutron source to a notional thermonuclear and prompt fission neutron spectrum to fulfill neutron source capability gaps. The experimental neutron environment was characterized with activation dosimetry, neutronics and covariance models, and unfolded to determine the as-fielded neutron spectrum. The first energy tuning assembly was demonstrated to create synthetic spectrally accurate post-detonation fission products, enhancing U.S. technical nuclear forensics capabilities. ATHENA, a second-generation energy tuning assembly, was also optimized to meet similar objectives, but the new platform neutron fluence efficiency was increased by a factor of …


Nuclear Data Covariance Analysis Of An Energy Tuning Assembly For Simulating Nuclear Weapon Environments, Nicholas J. Quartemont Mar 2019

Nuclear Data Covariance Analysis Of An Energy Tuning Assembly For Simulating Nuclear Weapon Environments, Nicholas J. Quartemont

Theses and Dissertations

An energy tuning assembly was characterized to spectrally shape the National Ignition Facility neutron source to a notional thermonuclear and prompt fission neutron spectrum to approximate a boosted nuclear device. This research performed nuclear data covariance analysis to predict the performance of the energy tuning assembly to create the objective spectrum, assessed anticipated experimental outcomes, and determine the fission products produced in a highly enriched uranium foil in the sample cavity. Nuclear data covariance impacted the neutron fluence energy distribution by a few percent for a large energy range of the neutron fluence. Neutron flux unfolding techniques provided broad spectral …