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Full-Text Articles in Nuclear Engineering

Exploring Laser Induced Breakdown Spectroscopy (Libs) For Post-Detonation Nuclear Forensics Debris Analysis, Justin Knoll, Chad Schools, David Fobar Mar 2019

Exploring Laser Induced Breakdown Spectroscopy (Libs) For Post-Detonation Nuclear Forensics Debris Analysis, Justin Knoll, Chad Schools, David Fobar

Purdue Workshop on Nonproliferation: Technology and Approaches

In the unlikely but catastrophic event of a nuclear terrorist attack our government leadership will need reliable information to rapidly inform critical decisions. This research explores the use of Laser Induced Breakdown Spectroscopy (LIBS) as a potential analysis tool in the National Technical Nuclear Forensics process. The current state of post detonation nuclear forensics requires ground and air samples be collected and shipped to state-of-the-art laboratories for radiochemical analysis. The samples undergo many measurements and useable data is produced as these measurements are completed. This data flows back into the process to guide additional measurements and inform the process of …


Incorporating Collisions And Resistance Into The Transition From Field Emission To The Space Charge Regime, Samuel D. Dynako, Adam M. Darr, Allen L. Garner Aug 2018

Incorporating Collisions And Resistance Into The Transition From Field Emission To The Space Charge Regime, Samuel D. Dynako, Adam M. Darr, Allen L. Garner

The Summer Undergraduate Research Fellowship (SURF) Symposium

Advancements in microelectromechanical systems (MEMS) and microplasmas, particularly with respect to applications in combustion and biotechnology, motivate studies into microscale gas breakdown to enable safe system design and implementation. Breakdown at microscale deviates from that predicted by Paschen’s law due to field emission—the stripping of electrons from the cathode in the presence of strong surface field—and follows the Fowler-Nordheim (FN) law. As injected current increases at this length scale, electrons accumulate in the gap and FN electron emission becomes space charge limited, leading to the Child-Langmuir (CL) law at vacuum and the Mott-Gurney (MG) law at high pressure. While theoretical …


Effect Of Helium Ions Energy On Molybdenum Surfaces Under Extreme Conditions, Joseph Fiala, Jitendra K. Tripathi, Sean Gonderman, Ahmed Hassanein Aug 2015

Effect Of Helium Ions Energy On Molybdenum Surfaces Under Extreme Conditions, Joseph Fiala, Jitendra K. Tripathi, Sean Gonderman, Ahmed Hassanein

The Summer Undergraduate Research Fellowship (SURF) Symposium

Plasma facing components (PFCs) in fusion devices must be able to withstand high temperatures and erosion due to incident energetic ion radiations. Tungsten has become the material of choice for PFCs due to its high strength, thermal conductivity, and low erosion rate. However, its surface deteriorates significantly under helium ion irradiation in fusion-like conditions and forms nanoscopic fiber-like structures, or fuzz. Fuzz is brittle in nature and has relatively lower thermal conductivity than that of the bulk material. Small amounts of fuzz may lead to excessive contamination of the plasma, preventing the fusion reaction from taking place. Despite recent efforts, …


Optical Emission Spectroscopy Diagnostics Of Cold Plasmas For Food Sterilization, Abhijit Jassem, Michael Lauria, Russell Brayfield Ii, Kevin M. Keener, Allen L. Garner Aug 2015

Optical Emission Spectroscopy Diagnostics Of Cold Plasmas For Food Sterilization, Abhijit Jassem, Michael Lauria, Russell Brayfield Ii, Kevin M. Keener, Allen L. Garner

The Summer Undergraduate Research Fellowship (SURF) Symposium

There is a growing need for economical, effective, and safe methods of sterilizing fresh produce. The most common method is a chlorine wash, which is expensive and may introduce carcinogens. High voltage cold atmospheric pressure plasmas are a promising solution that has demonstrated a germicidal effect; however, the responsible chemical mechanisms and reaction pathways are not fully understood. To elucidate this chemistry, we used optical emission spectroscopy to measure the species produced in the plasma generated by a 60 Hz pulsed dielectric barrier discharge in a plastic box containing various fill gases (He, N2, CO2, dry …


Hydrogen Loading System Development And Evaluation Of Tritiated Substrates To Optimize Performance In Tritium Based Betavoltaics, Thomas E. Adams Oct 2014

Hydrogen Loading System Development And Evaluation Of Tritiated Substrates To Optimize Performance In Tritium Based Betavoltaics, Thomas E. Adams

Open Access Dissertations

State-of-the-art hydrogen loading system onto thin metallic films based on differential pressure in calibrated chambers has been developed for conditions pressures and temperatures up to 69 bar and 500°C, respectively. Experiments on hydrogen loading on to palladium films of thickness 50 and 250 nm were conducted at pressure ranging from 0.2 bar to 10 bar at temperature 310°C. For first time film hydrogen loading was carried out at 1 bar and at room temperature which temperature. Beta flux exiting surface of metal tritide films has been modeled with MC-SET (Monte Carlo Simulation of Electron Trajectories in solids). Surface beta flux …


Developing Professional Skills In Stem Students: Data Information Literacy, Lisa Zilinski, Megan R. Sapp Nelson, Amy S. Van Epps Sep 2014

Developing Professional Skills In Stem Students: Data Information Literacy, Lisa Zilinski, Megan R. Sapp Nelson, Amy S. Van Epps

Libraries Faculty and Staff Scholarship and Research

Undergraduate STEM students are increasingly expected to have some data use skills upon graduation, whether they pursue post-graduate education or move into industry. This project was an initial foray into the application of data information literacy competencies to training undergraduate students to identify markers of data and information quality. The data consumer training appeared within two courses to help students evaluate data objects, including databases and datasets available on the Internet. The application of the Data Credibility Checklist provides a foundation for developing data reuse competencies. Based upon the initial presentation of the content, it became obvious that students need …


Double-Pulse Nd:Yag-Co2 Libs Excitation For Bulk And Trace Analytes, Jason R. Becker, Patrick Skrodzki, Prasoon Diwakar, Sivanandan Harilal, Ahmed Hassanein Aug 2014

Double-Pulse Nd:Yag-Co2 Libs Excitation For Bulk And Trace Analytes, Jason R. Becker, Patrick Skrodzki, Prasoon Diwakar, Sivanandan Harilal, Ahmed Hassanein

The Summer Undergraduate Research Fellowship (SURF) Symposium

Laser-induced breakdown spectroscopy [LIBS] is a commonly used technique for multi-element analyses for various applications such as space exploration, nuclear forensics, environmental analysis, process monitoring. The advantages of the LIBS technique include robustness, ease of use, field portability, and real-time, non-invasive multi-element analyses. However, in comparison to other lab based analytical techniques, it suffers from low precision and low sensitivity. In order to overcome these drawbacks, various approaches have been used, including double-pulse LIBS [DPLIBS]. Typically, various wavelength combinations of two Nd: yttrium aluminum garnet [YAG] lasers have been used for DPLIBS. However, the use of long wavelength (CO2 …


Doube-Pulse Laser-Induced Breakdown Spectroscopy Of Multi-Element Sample Containing Low- And High-Z Analytes, Patrick J. Skrodzki, Jason R. Becker, Prasoon K. Diwakar Ph. D., Sivanandan S. Harilal Ph. D., Ahmed Hassanein Ph. D. Aug 2014

Doube-Pulse Laser-Induced Breakdown Spectroscopy Of Multi-Element Sample Containing Low- And High-Z Analytes, Patrick J. Skrodzki, Jason R. Becker, Prasoon K. Diwakar Ph. D., Sivanandan S. Harilal Ph. D., Ahmed Hassanein Ph. D.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Laser-induced breakdown spectroscopy (LIBS) is a portable, remote, non-invasive analytical technique which effectively distinguishes neutral and ionic species for a range of low- to high-Z elements in a multi-element target. Subsequently, LIBS holds potential in special nuclear material (SNM) sensing and nuclear forensics requiring minimal sample preparation and detecting isotopic shifts which allows for differentiation in SNM (namely U) enrichment levels. Feasible applications include not only nonproliferation and homeland security but also nuclear fuel prospecting and industrial safeguard endorsement. Elements of higher mass with complex atomic structures, such as U, however, result in crowded emission spectra with LIBS, and characteristic …


Drift-Flux Correlation Development For Two-Phase Flow In Rod Bundles, Collin M. Clark Apr 2014

Drift-Flux Correlation Development For Two-Phase Flow In Rod Bundles, Collin M. Clark

Open Access Theses

A rod bundle drift-flux correlation is developed with intended application across a wide range of two-phase flow conditions. Special consideration is made for fluid flow mechanisms at low liquid velocity and low pressure conditions. In these instances, gravitational forces from the density difference of the associated fluid phases are more significant. Secondary flow patterns may develop as a result and a drift-flux correlation would need to make appropriate adjustments. Earlier correlations may have increased error at these conditions if they have been formulated with respect to relatively higher pressures or flow rates. In the present work, area-average void fraction data …


Response Of Plasma Facing Components In Tokamaks Due To Intense Energy Deposition Using Particle-In-Cell(Pic) Methods, Filippo Genco Oct 2013

Response Of Plasma Facing Components In Tokamaks Due To Intense Energy Deposition Using Particle-In-Cell(Pic) Methods, Filippo Genco

Open Access Dissertations

Damage to plasma-facing components (PFC) due to various plasma instabilities is still a major concern for the successful development of fusion energy and represents a significant research obstacle in the community. It is of great importance to fully understand the behavior and lifetime expectancy of PFC under both low energy cycles during normal events and highly energetic events as disruptions, Edge-Localized Modes (ELM), Vertical Displacement Events (VDE), and Run-away electron (RE). The consequences of these high energetic dumps with energy fluxes ranging from 10 MJ/m2 up to 200 MJ/m2 applied in very short periods (0.1 to 5 ms) can be …