Award Date


Degree Type


Degree Name

Master of Science in Engineering (MSE)


Mechanical Engineering

First Committee Member

Alexander Barzilov

Second Committee Member

Yi-Tung Chen

Third Committee Member

William Culbreth

Fourth Committee Member

Emma Regentova

Number of Pages



The purpose of this research was to analyze the capabilities of fast neutrons in the detection and analysis of various isotopes in bulk samples. The deuterium-tritium (DT) fusion reaction generates highly penetrating, high-energy (14.1-MeV) neutrons which induce nuclear reactions in irradiated targets. Neutrons and gamma rays are generated in these reactions. Emitted gamma rays are characteristic of the emitter; the gamma spectrum enables stoichiometric identification of the assayed samples. Neutron backscattering can also be used for identification of the elemental composition of the sample.

This work had three objectives. The first objective was to develop a computational technique to model the DT neutron-based assay. The second objective was to examine the in situ fast-neutron assay of Martian and Lunar regoliths for H2O. The third objective was to evaluate the nondestructive DT neutron assay of potentially hazardous compounds for applications in national security and defense. Each assay scenario was modeled using the Monte Carlo N-Particle code (MCNP). The astrochemistry scenarios assumed a potential robotic lander to carry the fast-neutron probe with optimal shielding and moderator components. The security scenario included a dual- mode (gamma rays and neutrons) detector for active interrogation of suspicious samples.

The Monte Carlo modeling data were analyzed using spectral processing routines developed in MATLAB, and subsequent determinations of stoichiometry of the samples and element’s detectability were made. Based on the study, an overall conclusion about the model’s viability for astrochemistry and security applications was made. Potential future work was considered.


Astrochemistry; Astrogeology; MCNP; Neutron


Nuclear | Nuclear Engineering

File Format


File Size

1700 KB

Degree Grantor

University of Nevada, Las Vegas




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