Date of Award

3-22-2019

Document Type

Thesis

Degree Name

Master of Science in Nuclear Engineering

Department

Department of Engineering Physics

First Advisor

James E. Bevins, PhD

Abstract

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 agreement between the energy tuning assembly and objective spectrum with an 80+% probability successful unfolding. ETAs sample fluence provides a short pulse neutron source with a 10 shake neutron pulse length. More than 1 billion fissions were produced which is on the order collected in nuclear forensics ground samples, and with current predictive capabilities had an equivalent cumulative fission product distribution to the objective spectrum.

AFIT Designator

AFIT-ENP-MS-19-M-089

DTIC Accession Number

DTIC pending

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