Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Nuclear forensics (3)
- Laser-induced breakdown spectroscopy (2)
- Machine learning (2)
- Actinide chemistry (1)
- Aeration rate (1)
-
- Analytical techniques (1)
- Anthrax (1)
- Artificial neural networks (1)
- Asteroid velocity (1)
- Bioaerosol (1)
- CANDU (1)
- Cerium (1)
- Chemical analysis (1)
- Chemometrics (1)
- Cross-section measurement (1)
- Deep level transient spectroscopy (1)
- Density function theory (1)
- Energy deposition (1)
- Free-floating carrier media (1)
- Germanium tin (1)
- Helium (1)
- Isotopic determination (1)
- Isotopic variance (1)
- LIBS (1)
- Laser induced breakdown spectroscopy (1)
- Lithium hydroxide monohydrate (1)
- Mass spectrometry (1)
- Monte-Carlo transport (1)
- Neutron detection (1)
- Neutron transport (1)
- Publication Type
Articles 1 - 12 of 12
Full-Text Articles in Engineering
Applications Of Portable Libs For Actinide Analysis, Ashwin P. Rao, John D. Auxier Ii, Dung Vu, Michael B. Shattan
Applications Of Portable Libs For Actinide Analysis, Ashwin P. Rao, John D. Auxier Ii, Dung Vu, Michael B. Shattan
Faculty Publications
A portable LIBS device was used for rapid elemental impurity analysis of plutonium alloys. This device demonstrates the potential for fast, accurate in-situ chemical analysis and could significantly reduce the fabrication time of plutonium alloys.
A Physics-Based Machine Learning Study Of The Behavior Of Interstitial Helium In Single Crystal W–Mo Binary Alloys, Adib J. Samin
A Physics-Based Machine Learning Study Of The Behavior Of Interstitial Helium In Single Crystal W–Mo Binary Alloys, Adib J. Samin
Faculty Publications
In this work, the behavior of dilute interstitial helium in W–Mo binary alloys was explored through the application of a first principles-informed neural network (NN) in order to study the early stages of helium-induced damage and inform the design of next generation materials for fusion reactors. The neural network (NN) was trained using a database of 120 density functional theory (DFT) calculations on the alloy. The DFT database of computed solution energies showed a linear dependence on the composition of the first nearest neighbor metallic shell. This NN was then employed in a kinetic Monte Carlo simulation, which took into …
The Effect Of Aeration Rate And Free-Floating Carrier Media On The Emission Of Bacillus Globigii In Bioaerosols, Andrew J. Owens
The Effect Of Aeration Rate And Free-Floating Carrier Media On The Emission Of Bacillus Globigii In Bioaerosols, Andrew J. Owens
Theses and Dissertations
Aerosols produced by turbulent mechanical mixing and bubble aeration at Waste Water Treatment Plants (WWTPs) become bioaerosols with the entrainment of biological materials. Bioaerosols become a public health risk when human pathogens are present. This study evaluated bioaerosols containing Bacillus globigii (BG) spores, and the effects that aeration rate and the addition of Free-Floating Carrier Media (FFCM) had on the amount of BG spores collected following aerosolization. A series of laboratory-scale experiments investigated two different sizes of floating polystyrene spheres as FFCM and four different aeration rates. When the differences in compared aeration rates were sufficiently large, a positive correlation …
Measurement Of The 160Gd(P,N)160Tb Excitation Function From 4 18 Mev, Using A Stacked Foil Technique, Ryan K. Chapman
Measurement Of The 160Gd(P,N)160Tb Excitation Function From 4 18 Mev, Using A Stacked Foil Technique, Ryan K. Chapman
Theses and Dissertations
A stack of thin Gd, Ti, and Cu foils were irradiated with an 18 MeV proton beam at Lawrence-Berkeley National Laboratory's 88-Inch Cyclotron to investigate the 160Gd(p,n)160Tb nuclear reaction for nuclear forensics applications. This experiment will improve knowledge of 160Tb production rates, allowing 160Tb to be efficiently created in a foil stack consisting of other proton induced isotopes for forensics applications. A set of 15 measured cross sections between 4-18 MeV for 160Gd(p,n)160Tb were obtained using a stacked foil technique. The foil stack consisted of one stainless steel, one iron, fifteen gadolinium, …
Neutron Energy Effects On Asteroid Deflection, Lansing S. Horan Iv
Neutron Energy Effects On Asteroid Deflection, Lansing S. Horan Iv
Theses and Dissertations
In the future, a hazardous asteroid will find itself on a collision course with Earth. It is an inevitability; the question is not if, but when. For asteroids of moderate size or larger, a nuclear device is one of humanity's only technologies capable of mitigating this threat via deflection on a timescale of less than a decade. This work examined how changing the output neutron energy from a nuclear device detonation affects asteroid deflection. The notional asteroid target was 300 meters in diameter and composed of silicon dioxide at a bulk density of 1.855 g/cm3. To calculate the …
An Assessment Of The Spatial Variation Of Isotopic Ratios In A Candu-6 Reactor For Nuclear Treaty Monitoring, Aaron W. Burkhardt
An Assessment Of The Spatial Variation Of Isotopic Ratios In A Candu-6 Reactor For Nuclear Treaty Monitoring, Aaron W. Burkhardt
Theses and Dissertations
The Preparatory Commission for the Comprehensive Nuclear Test Ban Treaty Organization developed the International Monitoring System for monitoring for nuclear explosive testing and compliance with nuclear treaties. Many of the International Monitoring System stations are capable of detecting radionuclides that can be used to determine their origin and creation environment. However, there is not a single unique signature associated with each creation environment. Nuclear reactors, for example, can have a wide range of isotopic concentrations caused by spatial variations in neutron flux intensity and energy. As a single sample only provides a single isotopic measurement, this can make disambiguation difficult …
Neutron Displacement Damage In Germanium Tin Photodiodes, Nathan J. Gale
Neutron Displacement Damage In Germanium Tin Photodiodes, Nathan J. Gale
Theses and Dissertations
GeSn is a promising material for photodiodes in the near-to-mid infrared (IR) spectrum because of new growth methods that enable integration with complementary metal oxide semiconductor (CMOS) technology. While natural germanium has a threshold wavelength of 1800 nm, 6.9 Sn content extends the threshold wavelength to 2700 nm based on a Sn content dependent bandgap. Also, unlike other semiconductors that require liquid nitrogen cooling to act as an IR sensor, GeSn can be operated at room temperature, enabling a wide variety of applications. In this study, photodiodes ranging from 0 to 6.9 tin content were subjected to 1 MeV (Si) …
A Machine Learning Approach To Characterizing Particle Morphology In Nuclear Forensics, Daniel A. Gum
A Machine Learning Approach To Characterizing Particle Morphology In Nuclear Forensics, Daniel A. Gum
Theses and Dissertations
A machine learning approach is taken to characterizing a group of synthetic uranium bearing particles. SEM images of these lab-created particles were converted into a binary representation that captured morphological features in accordance with a guide established by Los Alamos National Laboratory. Each particle in the dataset contains an association with chemical creation conditions: processing method, precipitation temperature and pH, calcination temperature are most closely tied to particle morphology. Additionally, trained classifiers are able to relate final products between particles, implying that morphological features are shared between particles with similar composition.
Rapid Analysis Of Plutonium Surrogate Material Via Hand-Held Laser-Induced Breakdown Spectroscopy, Ashwin P. Rao
Rapid Analysis Of Plutonium Surrogate Material Via Hand-Held Laser-Induced Breakdown Spectroscopy, Ashwin P. Rao
Theses and Dissertations
This work investigated the capability of a portable LIBS device to detect and quantify dopants in plutonium surrogate alloys, specifically gallium, which is a common stabilizer used in plutonium alloys. The SciAps Z500-ER was utilized to collect spectral data from cerium-gallium alloys of varying gallium concentrations. Calibration models were built to process spectra from the Ce-Ga alloys and calculate gallium concentration from spectral emission intensities. Univariate and multivariate analysis techniques were used to determine limits of detection of different emission line ratios. Spatial mapping measurements were conducted to determine the device's ability to detect variations in gallium concentration on the …
Determination And Simulation Of The Neutron Spectrum Of Nuclear Detonations And Surrogate Sources, Taylor M. Nichols
Determination And Simulation Of The Neutron Spectrum Of Nuclear Detonations And Surrogate Sources, Taylor M. Nichols
Theses and Dissertations
This research determined a methodology for characterizing the Fast Beam Facility (FBF) at The Ohio State University Nuclear Reactor Laboratory to test the response of photovoltaic arrays to nuclear weapon radiation. Additionally, this research developed neutron and gamma nuclear weapon output spectra of two environments for comparison to the FBF spectrum. A Bonner sphere spectrometer (BSS), coupled with the unfolding program Maximum Entropy Deconvolution (MAXED), was employed as a means of determining the energy spectrum of neutrons. Using the ISO 8529 americium beryllium (AmBe) source as the a priori default spectrum, MAXED was used to unfold the spectrum of neutrons …
Analysis Of The Correlation Between Re Filament Surface Features And Tims Performance, Christopher J. Mihal
Analysis Of The Correlation Between Re Filament Surface Features And Tims Performance, Christopher J. Mihal
Theses and Dissertations
Thermal Ionization Mass Spectrometry (TIMS) is an invaluable tool in nuclear forensics as it enables isotopic assays of actinides to be measured, permitting analysis to include special nuclear material isotopic assays, nuclear reactor monitoring, and treaty verification. In one method of measurement for the TIMS system, samples are deposited in solution form on high-purity rhenium filaments. The filaments are heated to evaporate the solvent, and then further heated to cause sample ionization, permitting the sample to be transmitted through a magnetic field which separates ions based on mass to charge ratio into detectors for counting. Heavier ions will be deflected …
Determination Of Lithium Isotope Concentration By Laser Induced Breakdown Spectroscopy Using Chemometrics, Jason C. Wood
Determination Of Lithium Isotope Concentration By Laser Induced Breakdown Spectroscopy Using Chemometrics, Jason C. Wood
Theses and Dissertations
The role of enriched 6Li in nuclear applications makes the ability to detect and monitor lithium enrichment activity imperative. Detecting levels of enrichment of this isotope currently requires sensitive, complex equipment operated by highly-trained technicians, which is prohibitive to rapid detection of enrichment activity. While commercial companies market portable laser induced breakdown spectroscopy (LIBS) with the ability to detect elements on the order or parts per million concentrations, they have not yet been demonstrated to possess the ability to quantitatively determine isotopic concentrations of lithium. This research performs single-pulse LIBS experiments under laboratory conditions to determine concentrations of 7Li and …