Date of Award
Master of Science in Nuclear Engineering
Department of Engineering Physics
Darren Holland, PhD
The goal of this work was to use the adjoint transport equation to characterize the energy spectrum of a point neutron source using the time-energy fluence at the satellite. The adjoint transport was solved via Monte Carlo methods in the new program called Space to Air High-Altitude Region Adjoint (SAHARA). A new adjoint source event estimator was developed to improve the computational efficiency. This work explores SAHARA’s performance using mono-energetic and continuous sources. In general, the identified source spectra were noticeably shifted towards lower energies, but were able to capture the source spectrum shapes. Lastly, SAHARA was applied to the real-world neutron energy spectrums of Fat Man and Little Boy. SAHARA provides a new tool for estimating the source spectrum from space-based neutron measurements.
DTIC Accession Number
LaMere, Zachary W., "Space to High-Altitude Region Adjoint Neutron Transport" (2021). Theses and Dissertations. 5020.