Date of Award


Document Type


Degree Name

Master of Science


Department of Engineering Physics

First Advisor

Stephen R. McHale, PhD.


A stacked array of segmented micro-structured semiconductor neutron detectors (MSNDs) has been fabricated to perform as a neutron spectrometer simultaneously capable of differentiating fast and thermal neutrons. The MSND devices consist of thin-film perforated diodes constructed from LiF powder back-filled into an etched silicon wafer. Geant4 simulations demonstrate than an eight-layer spectrometer consisting of alternating layers of MSND and hydrogenous moderator can successfully resolve neutron energies at a resolution dependent upon the number of layers and the thickness of the adjacent moderating materials. The simulated spectrometer response was compared to that obtained experimentally with mono-energetic neutrons from a D+D neutron generator. The commissioning tests of the spectrometer reveal that the energy of a mono-energetic neutron source can be identified to within + or -1 MeV. Following the commissioning tests, the spectrometer was used to characterize the poly-energetic neutron spectrum of a plutonium-beryllium neutron source.

AFIT Designator


DTIC Accession Number


Included in

Nuclear Commons