Nuclear Engineering Commons^™

Neutron-Gamma Discrimination In Elpasolite Scintillator Detector, Brittany Morgan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Existing nuclear stockpiles and weapons-making capabilities imperil the global community. Current nonproliferation efforts involve the research and development of newer, more efficient detection systems that can be deployed for the interdiction and monitoring of special nuclear materials (SNM). Spontaneous and induced fission events in SNM produce neutrons and gamma rays, which can be detected and analyzed, in particular, using scintillator detectors. Various electronic data acquisition systems and data analysis methods have been employed to record and characterize neutron and photon signatures. The goal of this thesis is to develop a new method of discrimination between neutrons and photons in the …

Investigation Of 186Re Via Radiative Thermal-Neutron Capture On 185Re, David A. Matters, Andrew G. Lerch, A. M. Hurst, L. Szentmiklosi, J. J. Carroll, B. Detwiler, Zs. Revay, John W. Mcclory, Stephen R. Mchale, R. B. Firestone, B. W. Sleaford, M. Krticka, T. Belgya

Faculty Publications

Partial ��-ray production cross sections and the total radiative thermal-neutron capture cross section for the ¹⁸⁵Re(n,��)¹⁸⁶Re reaction were measured using the Prompt Gamma Activation Analysis facility at the Budapest Research Reactor with an enriched ¹⁸⁵Re target. The ¹⁸⁶Re cross sections were standardized using well-known ³⁵Cl(n,��)³⁶Cl cross sections from irradiation of a stoichiometric ^natReCl₃ target. The resulting cross sections for transitions feeding the ¹⁸⁶Re ground state from low-lying levels below a cutoff energy of E_c=746keV were combined with a modeled probability of ground-state feeding from levels above E …

Cosmic Ray Muons For Spent Nuclear Fuel Monitoring, Stylianos Chatzidakis

Open Access Dissertations

There is a steady increase in the volume of spent nuclear fuel stored on-site (at reactor) as currently there is no permanent disposal option. No alternative disposal path is available and storage of spent nuclear fuel in dry storage containers is anticipated for the near future. In this dissertation, a capability to monitor spent nuclear fuel stored within dry casks using cosmic ray muons is developed. The motivation stems from the need to investigate whether the stored content agrees with facility declarations to allow proliferation detection and international treaty verification. Cosmic ray muons are charged particles generated naturally in the …

Nanoscale Phonon Thermal Conductivity Via Molecular Dynamics, Jonathan M. Dunn

Open Access Theses

Molecular dynamics (MD) simulations provide a useful and simple means of calculating the nanoscale thermal properties of materials, which requires special analysis since the thermal properties of materials change when their dimensions reach the nanoscale. In this research, MD is used to investigate the nanoscale phonon thermal transport of materials that are attracting much interest in the areas of materials science and nuclear physics. In order to evaluate two distinct methods of calculating the thermal conductivity of materials using MD, the simulation methods are first applied to Si. Once an understanding of each simulation method is established, they are then …

Method To Fabricate Portable Electron Source Based On Nitrogen Incorporated Ultrananocrystalline Diamond (N-Uncd), Anirudha V. Sumant, Ralu Divan, Chrystian M. Posado, Carlos Henry Castano Giraldo, Edwin J. Grant, Hyoung-Koo Lee

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

A source cold cathode field emission array (FEA) source based on ultra-nanocrystalline diamond (UNCD) field emitters. This system was constructed as an alternative for detection of obscured objects and material. Depending on the geometry of the given situation a flat-panel source can be used in tomography, radiography, or tomosynthesis. Furthermore, the unit can be used as a portable electron or X-ray scanner or an integral part of an existing detection system. UNCD field emitters show great field emission output and can be deposited over large areas as the case with carbon nanotube “forest” (CNT) cathodes. Furthermore, UNCDs have better mechanical …

Neutron Versus Gamma Radiation Effects On Ytterbium-Doped Optical Fibers, Olivia M. Borman

Theses and Dissertations

Multimode ytterbium-doped optical fibers (YDFs) are increasingly utilized in military applications involving fiber lasers and amplifiers. YDFs were irradiated with three different radiation sources (neutron, gamma, and mixed gamma/neutron) in order to determine the independent effects that gamma and neutron radiation have on the fibers. The transmission spectra of the fibers were measured during each irradiation and the spectral shapes and attenuation were compared at similar doses. Comparisons of the spectra showed that gamma radiation results in increased attenuation over the 550-975 nm wavelengths. Fast neutrons were found to contribute to increased attenuation near 500 nm. Neutron radiation also caused …

Radiation Response From A Novel Uo2 Crystal, Stephan A. Varga

Theses and Dissertations

The radiation response of a novel, single-crystalline UO2 sample was analyzed using several types of radiation. The crystal was exposed to alpha, gamma, and neutron radiation under various environmental conditions and the electronic response of the crystal was measured using a pulse shape discrimination algorithm. The distributions of pulse amplitude (Vmax) and pulse decay times (τ) were used to compare the output. This research revealed that the crystal radiation response is exceptionally sensitive to surface conditions, specifically humidity, which tends to alter the time dependent currents resulting from the radiation interactions. The pulse τ can be made to …

Evaluation Of The Visible Infrared Imaging Radiometer Suite (Viirs) Cloud Base Height (Cbh) Pixel-Level Retrieval Algorithm For Single-Layer Water Clouds, Kyle E. Fitch

Theses and Dissertations

Evaluation of the Visible Infrared Imaging Radiometer Suite (VIIRS) Cloud Base Height (CBH) product was accomplished. CBH is an important factor for aviation, but a lack of coverage for ground-based retrieval is a significant limitation. Space-based retrieval is essential; therefore, the VIIRS CBH pixel-level retrieval algorithm was assessed for single-layer water clouds. Accurate (truth) measurements were needed not only for the CBH product, but also for VIIRS cloud optical thickness (COT), effective particle size (EPS), and cloud top height (CTH). Data from Atmospheric Radiation Measurement (ARM) sites were used, with VIIRS-ARM matchups created from June 2013 through October 2015 for …

Differential (P, P′) And (P, D) Cross Sections Of 89Y And 92Zr, Molly A. Wakeling

Theses and Dissertations

Differential cross sections for the (p, p′) and (p, d) reactions on ⁸⁹Y and ⁹²Zr were measured using a 28.25-MeV proton beam at the 88-inch cyclotron at Lawrence Berkeley National Laboratory. Angular distributions were obtained for the ground state and several excited states of each isotope using silicon detector telescopes over angles 10° to 140° in the reaction plane. These data were obtained by fitting a Gaussian function to each peak in the energy spectra and integrating the number of counts under each peak. These cross sections will be included in nuclear structure models …

Analysis Of Neutron Effects For Asteroid Disruption, Aaron J. Ferguson

Theses and Dissertations

The use of nuclear weapons is one possible method for disrupting or deflecting an asteroid on a trajectory to impact the earth. A largely unexplored component of weapon yield in a disruption scenario is the impact of the neutron output. The results of MCNP-6 simulations are presented demonstrating the effect that incident neutron energy has on the total energy deposited in an asteroid, including that the efficiency of energy deposition in a material is inversely proportional to the incident neutron energy due to negative Q-value reactions. The effects of material composition on the total energy deposited as well as the …

Nuclear Forensics Applications Of Principal Component Analysis On Micro X-Ray Fluorescence Images, Sarah T. Castro

Theses and Dissertations

A method is developed for rapid detection and analysis of actinides and correlated materials in nuclear fallout debris using principal component analysis on quantified micro x-ray fluorescence intensity values. This method is then applied to address goals of nuclear forensics. The first implementation is a collaborative effort with the National Institute of Standards and Technology and the Federal Bureau of Investigation Laboratory to produce a standard reference material that is a surrogate for glassy nuclear fallout debris in a modern urban environment. This reference material will enable researchers in the development and validation of nuclear forensics methods. A method for …

Applications Of Correlated 2d-Acar And Cdbar Using A Low-Energy Positron Beam, Angelo M. Bonavita

Theses and Dissertations

The three-dimensional positron annihilation spectroscopy system (3D-PASS) at the Air Force Institute of Technology (AFIT) correlates coincidence Doppler broadening of annihilation radiation with two-dimensional angular correlation of annihilation radiation measurements using two position-sensitive, high-purity germanium (HPGe) detectors. The low photoelectric cross section of germanium, combined with the limited output of the radioisotope-based positron beam, produced sparse data necessitating careful data extraction. Processing techniques employed to increase 3D-PASS spectra quality include an improved algorithm for determining radiation-interaction position on HPGe double-sided strip detectors, a momentum sampling function based correction scheme and spectra folding informed by crystal symmetries. The 3D nature of …

Neutron Radiation Effects On Ge And Gesn Semiconductors, Christopher T. O'Daniel

Theses and Dissertations

Two different semiconductor materials received neutron radiation for assessment of radiation damage. The two materials are undoped bulk Ge and epitaxial Ge_0.991Sn_0.009, which is doped heavily with phosphorous. At room temperature, the Ge sample has direct and indirect bandgaps at 0.78 eV and 0.66 eV, respectively. The Ge_0.991Sn_0.009 sample has direct and indirect bandgaps at 0.72 eV and 0.63 eV, respectively. Two samples of each material were exposed to research reactor neutrons, delivering a 1 MeV equivalent neutron fluence of 2.52 × 10¹⁵ n/cm². In order to assess the radiation …

Temperature Measurements During High Flux Ion Beam Irradiations, M. L. Crespillo, Joseph T. Graham, Y. Zhang, W. J. Weber

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

A systematic study of the ion beam heating effect was performed in a temperature range of -170 to 900 °C using a 10 MeV Au³⁺ ion beam and a Yttria stabilized Zirconia (YSZ) sample at a flux of 5.5 x 10¹² cm^-2 s^-1. Different geometric configurations of beam, sample, thermocouple positioning, and sample holder were compared to understand the heat/charge transport mechanisms responsible for the observed temperature increase. The beam heating exhibited a strong dependence on the background (initial) sample temperature with the largest temperature increases occurring at cryogenic temperatures and decreasing with increasing temperature. …

A Simulation Study Of A Radiofrequency Localization System For Tracking Patient Motion In Radiotherapy, Mark Ostyn, Siyong Kim, Woon-Hong Yeo

Mechanical and Nuclear Engineering Publications

One of the most widely used tools in cancer treatment is external beam radiotherapy. However, the major risk involved in radiotherapy is excess radiation dose to healthy tissue, exacerbated by patient motion. Here, we present a simulation study of a potential radiofrequency (RF) localization system designed to track intrafraction motion (target motion during the radiation treatment). This system includes skin-wearable RF beacons and an external tracking system. We develop an analytical model for direction of arrival measurement with radio frequencies (GHz range) for use in a localization estimate. We use a Monte Carlo simulation to investigate the relationship between a …

Alternative Materials For Dental Restorations, Tyler Poole, Pierce Dunwoody, Adarsha Sapkota, Mario Rodriguez

Capstone Design Expo Posters

The senior design project ‘Alternative Materials and Methods for Dental Restoration’ has a purpose of addressing the unmet need or engineering problem related to dental restoration by determining the available manufacturing methods and materials as an alternative to ‘Intra-oral digital scanners’. The project deliverables for this project were the tooth crown prototypes with the tolerance within 50 microns. The CAD model for this tooth was tested for its strength, physical properties, and suitability. The prototypes were developed through an additive method, i.e., 3D printing. The constraints for this project were related to budget and printer. Buying a highly qualitative 3D …

Vcu Neuroguard: Multi-Person Radiation Shielding Device, David Bauserman, Abigail Haines, Laynold Pilson, Madelaine Simmons

Capstone Design Expo Posters

The objective of the VCU Neuroguard project was to design and build a device to shield all medical personnel in Operating Room-33, at MCV Hospital, from radiation during neurological procedures that utilize a Siemens Artis Zee biplane X-ray machine. The initial goal was to develop a fully working prototype but due to monetary reasons this goal was adjusted to a working prototype minus the radiation shielding materials.

There were many requirements for the VCU Neuroguard set forth by the customer and by the team, including the ability to shield all the medical staff in the room, the ability for them …

Improved Way To Affix Iv Components To Gurneys From Operating Tables, Corey Gilbert, Braulio Rosales, Jason Warren

Capstone Design Expo Posters

The current issue in the process of transporting a patient from the operating room (OR) to the intensive care unit (ICU) is the risks involved with the IV stand being top-heavy due to two or three IV pumps weighing approximately 15 pounds each. This can lead to injury to the patient, or other personnel, if an instance occurred where the IV stand were to tip over. Having a single person to manage both the IV stand and gurney during transport can increase this risk.

To remedy these problems, the project team established the goals of developing a working prototype, testing …

Design And Optimization Of A Molten Metal Loop Driven By An Electromagnetic Pump, Eric Mallon, Miguel Bustamante Perez, Joseph Keegan

Capstone Design Expo Posters

Liquid Metal Fast Reactor (LMFR) utilizing liquid metal as a coolant is still being considered for future nuclear energy. In this concept, transporting liquid metal still poses many challenges in engineering design and material detection and accountability. In this senior design project, the team has been exploring a design and optimization of a molten metal loop driven by an electromagnetic pump. Here, a manometer type solution was deemed the best method to achieve meaningful results. Transparent Pyrex tubing was selected for the manometers, as the visual column difference would indicate pressure differences. Tin was selected for the working fluid, and …

Emergency Glucagon Injection Device, John Corbett, Zachary Cullingsworth, Christopher Ducic, Ryan Meekins

Capstone Design Expo Posters

Glucagon is a drug administered to people with diabetes that are experiencing a seizure due to low blood glucose levels. The current method of injecting glucagon during a hypoglycemic seizure is lengthy and complicated when time equates to minimizing the effects of an emergency situation. This project is student created and the result of the design team recognizing a serious problem and deciding to find a better solution. The goal of this project was to streamline this process. Several working prototypes were developed and evaluated before a final design was chosen. Safety, durability and usability were all considerable factors. The …

Thermo-Regulated Device For Extremities Affected By Raynaud’S Disease, Jessica L. Bishop, Nathaniel P. Kirby, T. Ryan Beaver, Alisa B. Sverdlov

Capstone Design Expo Posters

Raynaud’s condition is a disease in which blood vessels in the extremities constrict in response to emotional stimuli and cold environments. This results in extreme discoloration and pain in the regions affected (Figure 1), and can cause permanent tissue damage. Although there is no current cure for this disease, there are several methods of pain mitigation including the use of drugs, gloves, avoiding exposure to cold weather, and using heating devices. However, these solutions are only temporary. Most gloves do not provide adequate insulation or have a short battery life.

This project is aimed at mediating the negative physiological effects …

Non-Destructive Testing Of Hardface Cladding, Hunter Andrews, Karson Clark, Jared O’Hara

Capstone Design Expo Posters

Valves, such as the ones shown in Figure 1 and Figure 2, are very common throughout Navy vessels in systems which transport various materials such as water, steam, and oil. Over their lifetime the valve Stellite seatings are rehabilitated by being ground down to create a smooth surface. If the seating surface is ground to a thickness lower than 3/32 in, the valve will be considered inoperable. It was necessary to design a portable device that can be used by Newport News Shipbuilding to measure the thickness of Stellite coatings on valve seating surfaces. A device that could be used …

Tapered Roller Bearing Accelerated Life Test Rig Design And Fabrication, Laith Naeem, Andrew Nguyen, Bryson Sin, Ramon Vargas

Capstone Design Expo Posters

L₁₀ bearing fatigue life testing is a costly and prolonged process, as the bearing is characteristically designed for durability and reliability. Within the current testing methods, faulty materials still have the potential of passing the test. However, with this life test rig, the bearing will be tested to failure, thus providing an indicator for its predicted life span.

The purpose of this project is to optimize and construct a L₁₀ life test rig for accelerated fatigue testing of the Association of American Railroad Class K, 6 ½ x 9-inch double-row tapered roller bearing to their maximum fatigue life …

Underhull Material Transport Rig: Aircraft Carrier Maintenance Processes, Hunter Alford, Christopher Brady, Michelle Runion, Spencer Trevisan

Capstone Design Expo Posters

The clearance under a ship in the Newport News Shipbuilding dry dock is approximately 62 inches. As a result, workers are either crouched or hunched over as they carry materials and equipment underneath the ship to their work zone. This can cause physical strain on workers’ bodies, leading to safety and health problems. This design project solves the problem by creating a transport system that uses a cart suspended from two trolleys that ride on a track attached to the bottom of the hull.

A working prototype was built, demonstrated, and tested. This prototype cart maneuvered through a straight and …

Robotic Inspection Of Geometrically Complex Tank Systems, Andrew Casalenuovo, Andrew Rubio, Charles Hockett, Peter Donaldson

Capstone Design Expo Posters

The goal of this project was to continue the development of a temporary rail system for a robotic tank inspection device. The tanks to be inspected are in a hazardous environment that is dangerous to work in and navigate. A remotely controlled robot could reduce the need for manual labor in the tanks to initial setup, final removal, and touch ups. Similar setups have been created for inspecting tanks, but they are permanent installations and are meant only for inspections.

The goal of the current phase of the project was to employ a new concept for supporting the rail system, …

Highway 66 Structural Foundation Redesign, Devyn Borum, Joshua Clarke, Lorenzo Dingcong, Korey Smith

Capstone Design Expo Posters

The primary project goal was to reduce the cost per unit of the structural foundation (sublane) of the Route 66 miniature bowling lane by 10%. Additional project goals were: 1) reducing the cubic volume for shipping, (2) reducing the lane assembly time, and 3) maintaining current 10 to 15-year product life. Ten sublane sections are used to assemble two lanes of a Route 66 unit. The project constraints included: 1) maintaining outside height, width and length of the sublanes, 2) load bearing strength greater than or close to the current design and 3) no significant change in manufacturing processes. After …

Friction And Wear Measurements In Automatic Transmission Clutch, Steffen Harm, Dabin Kim, Jean Paulo Mulles, Eric Stavitzski, Hoang Tran

Capstone Design Expo Posters

In order to create alternate pathways to increase fuel efficiency, flexible ways to alter and test fluid properties are needed when transmission manufacturers change the operating conditions or components used in automatic transmissions. A prototype was fabricated to satisfy this need by reducing the cost, time of conducting tests while producing accurate results, and also increasing the amount of trials that can be conducted in a laboratory setting. The limitations of developing a new prototype are: safety, weight, ease of use, laboratory size, and establishing accurate results within the amount of time given. This project was approached using the Engineering …

3d Heart Model For Mapping Rf Ablation Sites, Danielle Corsino, Ashleigh Mims, Andrew Potter, Alejandro Rivera

Capstone Design Expo Posters

Electro-Cardiologists routinely insert radiofrequency probes into the heart and conduct targeted ablation procedures to correct irregular heartbeats. Current techniques are very experience and “touch” based, and require the novice cardiologist about 50 procedures to become proficient. There is a need for a functional heart model device that can be used to reduce the amount of procedures on human patients before cardiologist become proficient. Project constraints included limited software availability for segmenting accuracy, available 3D printing technology and materials, and cost to 3D print heart models due to the complex geometry. The team began with a CT scan, ITK SNAP and …

3d Printed Teeth: Anatomically Correct Primary Replicas, Anh Nguyen, Stefan Harris

Capstone Design Expo Posters

The current method of molding teeth, especially primary teeth, cannot accurately reproduce internal tooth structures. Therefore, there is a need for primary teeth to be made anatomically accurate on-demand with the ability to customize a model for specific patients. This project aims that any tooth extracted digitally from a Dental Cone Beam computed tomography (CBCT) scan of a child's mouth can be 3D printed into an accurate replicate with which dental students can practice. Constraints include viable materials that can be printed by a 3D printer, represent tooth anatomy and provide desirable mechanical properties compatible with the dental drilling operation. …

Adjustable Pipe Hanger: Newport News Shipbuilding, Ryan Fitzgerald, Ahmad Othman, Emily Holland, Zinullah Ghaznawi

Capstone Design Expo Posters

This senior design project is sponsored by Newport News Shipbuilding. The objective of this project is to design a pipe hanger system that could be installed during initial fabrication while still allowing adjustment when the pipe path deviates from the initial drawings. The design must be cheap and utilize already existing parts. One key constraint is to hold a load of 250 pounds and withstand a velocity between 100-120 inches per second. The original design created utilizes a C-channel track attached to the ceiling and a spring locking mechanism to provide flexibility. This final design eliminated the spring device with …