Unfolding neutron energy spectra with a passive neutron spectrometer

Ph.D. thesis

Zachary T. Condon
Richard Vasques (Advisor), Vaibhav Sinha (Co-Advisor), Ph.D. in Nuclear Engineering, The Ohio State University, Columbus, OH, 2024 Jul

Dissertation Zachary T. Condon

Cite

APA Click to copy
Condon, Z. T. (2024, July). Unfolding neutron energy spectra with a passive neutron spectrometer (PhD thesis). (R. V. (Advisor) & V. S. (Co-Advisor), Eds.), Ph.D. in Nuclear Engineering. The Ohio State University, Columbus, OH.

Chicago/Turabian Click to copy
Condon, Zachary T. “Unfolding Neutron Energy Spectra with a Passive Neutron Spectrometer.” Edited by Richard Vasques (Advisor) and Vaibhav Sinha (Co-Advisor). Ph.D. in Nuclear Engineering. PhD thesis, The Ohio State University, 2024.

MLA Click to copy
Condon, Zachary T. “Unfolding Neutron Energy Spectra with a Passive Neutron Spectrometer.” Ph.D. in Nuclear Engineering, edited by Richard Vasques (Advisor) and Vaibhav Sinha (Co-Advisor), The Ohio State University, July 2024.

BibTeX Click to copy

@phdthesis{zachary2024a,
  title = {Unfolding neutron energy spectra with a passive neutron spectrometer},
  year = {2024},
  month = jul,
  address = {Columbus, OH},
  journal = {Ph.D. in Nuclear Engineering},
  school = {The Ohio State University},
  author = {Condon, Zachary T.},
  editor = {(Advisor), Richard Vasques and (Co-Advisor), Vaibhav Sinha},
  month_numeric = {7}
}

Dr. Zachary Condon

ABSTRACT: Acquiring accurate neutron energy spectrum information is of vital importance to national security as well as personal safety. Unfolding neutron energy spectra from detector responses is a heavily researched area due to the importance of neutron energy for determining radiation dose received. A new detection system developed by Lawrence Livermore National Laboratory (LLNL), the passive neutron spectrometer (PNS), is being investigated for use in energy spectrum unfolding techniques primarily in the event of a criticality accident. The unfolded energy spectrum is used to calculate the dose a person would receive in the presence of that neutron field. This detector provides a passive neutron detection method through the use of 55 thermoluminescent dosimeters or gold foils contained within a single polyethylene sphere. Three unfolding algorithms were employed in this research: MAXED, a well-established unfolding code; Neutron Energy Spectrum Reconstruction (NESR), a code developed in-house at LLNL; and a neural network technique was developed and utilized. Through the use of calculated detector responses and each of the unfolding algorithms, the PNS is first verified that it provides the information needed for unfolding neutron spectra. After verifying the PNS, multiple experimental PNS detector responses were unfolded and the expected dose was calculated. Where available, the calculated dose was compared to the expected dose to determine if the unfolding techniques were able to meet the DoE standards, which state that unfolded doses should be within 30% of each other.