Author ORCID Identifier
Date Available
4-26-2019
Year of Publication
2019
Degree Name
Doctor of Philosophy (PhD)
Document Type
Doctoral Dissertation
College
Arts and Sciences
Department/School/Program
Physics and Astronomy
First Advisor
Dr. Michael A. Kovash
Abstract
Despite nuclear fission prominence in nuclear physics, there are still several fundamental open questions about this process. One uncertainty is the energy distribution of neutrons emitted immediately after fission. In particular the relative energy distribution of neutrons above 8~MeV has been difficult to measure. This experiment measured the prompt neutron energy spectrum of n+235U from 3-10~MeV. The measurement took place at Los Alamos National Laboratory (LANL) and used a double time-of-flight technique to measure both the beam and fission neutron kinetic energies. Fission event timing was measured with a parallel plate avalanche counter. The fission neutron time-of-flight was measured with 2~m long plastic scintillation detectors. By combining the time-of-flight information with a known flight path the kinetic energy spectrum of neutrons was measured. To eliminate backgrounds various time-of-flight and energy cuts were imposed and an accidental coincidence background was subtracted. An MCNP simulation, including the 2~m neutron detector geometry, was done using the Madland and Nix model as the input energy distribution for the simulated neutrons. Finally, the measured energy spectrum was compared with the MCNP simulated n+235U fission neutron energy spectrum.
Digital Object Identifier (DOI)
https://doi.org/10.13023/etd.2019.179
Funding Information
This research was supported by the US Department of Energy grant DE-NA0003348.
Recommended Citation
McGinnis, Jason M., "PROMPT FISSION NEUTRON ENERGY SPECTRUM OF n+235U" (2019). Theses and Dissertations--Physics and Astronomy. 63.
https://uknowledge.uky.edu/physastron_etds/63
