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Full-Text Articles in Nuclear Engineering

Graphene Field Effect Transistor For Radiation Detection On A Micron To Millimeter Scale, Peter C. Lamm, Robert Speer Bean, Zachary Shollar Aug 2015

Graphene Field Effect Transistor For Radiation Detection On A Micron To Millimeter Scale, Peter C. Lamm, Robert Speer Bean, Zachary Shollar

The Summer Undergraduate Research Fellowship (SURF) Symposium

Novel technology in radiation detection is critical to advancing radiation detectors for their many applications. Graphene has shown to be able to change its conductivity in the presence of an electric field; this makes it an excellent candidate to be used as a radiation detector for the detection of the charges generated during radiation interactions. Research has been done on making micron scale graphene field effect transistors (GFET) with graphene on a Si/SiO2 wafer, but it is critical that we try to increase the scale. Unknowns persist in scaling graphene to millimeter sizes. This study plans to elucidate any …


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, …


Effect Of Carbon Impurity On Molybdenum Nanostructure Evolution Under Helium Ion Irradiation In Extreme Conditions, Nikhil A. Bharadwaj, Jitendra Tripathi, Ahmed Hassanein, Sean Gonderman Aug 2015

Effect Of Carbon Impurity On Molybdenum Nanostructure Evolution Under Helium Ion Irradiation In Extreme Conditions, Nikhil A. Bharadwaj, Jitendra Tripathi, Ahmed Hassanein, Sean Gonderman

The Summer Undergraduate Research Fellowship (SURF) Symposium

The performance of plasma facing components (PFC) is of great important for the realization of prototype nuclear fusion. Tungsten has been considered as the leading high-Z PFC material for these reactors and tokamaks due to its superior thermophysical properties, high melting point, low sputtering yield, and low tritium inventory. However, its surface deteriorates significantly under helium ion irradiation in extreme (fusion) conditions and forms nanoscopic fiber like structures (fuzz) Recent studies show that the formation of fuzz nanostructure on tungsten can be suppressed by the presence of plasma impurities such as carbon and beryllium. In the present study, the effects …


Quantum Modeling Of Thermodynamic Properties Of Warm Dense Aluminum, Nicholas Termini, Gennady Miloshesky, Ahmed Hassanein Aug 2015

Quantum Modeling Of Thermodynamic Properties Of Warm Dense Aluminum, Nicholas Termini, Gennady Miloshesky, Ahmed Hassanein

The Summer Undergraduate Research Fellowship (SURF) Symposium

Warm dense matter is attracting a lot of attention in the scientific community, due to its formation during intense laser-matter interaction and inertial confinement fusion. However, there is no accurate solution to mapping out the thermodynamic properties of warm dense matter. Experimental data are also incredibly scarce making computational models an incredibly useful tool. This paper provides equation of state (EOS) data for aluminum at specific densities within the warm dense matter regime. The EOS data were calculated using quantum molecular dynamics, which was performed by the computational package QuatumEspresso. EOS were determined by collecting and recording pressure after achieving …


Temperature Dependence Of Electrical Performance Of Tritium Sourced Betavoltaic Cells, Darrell S. Cheu, Tom Adams, Shripad Revankar Aug 2015

Temperature Dependence Of Electrical Performance Of Tritium Sourced Betavoltaic Cells, Darrell S. Cheu, Tom Adams, Shripad Revankar

The Summer Undergraduate Research Fellowship (SURF) Symposium

There is an increasing need for devices that can be powered for extended periods of time where it is impossible for maintenance or replacement, such as pacemakers, long term space flight or undisturbed sensors for military use. Since 1971, most devices run off a Lithium-Iodide battery, which gives a high amount of power but could only last approximately 2 to 5 years, requiring frequent replacement. However, replacement is unnecessary for betavoltaic cells as they can last at least 20 years. Commercially available tritium betavoltaic cells provided by City Labs Inc. were tested at a temperature range of -50°C to 150°C …


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 …


Cold Atmospheric Plasma: An Inside Look Through Optical Diagnostics For Biomedical Applications, Liesl Krause, Ahmed Hassanein, Prasoon Diwakar Aug 2015

Cold Atmospheric Plasma: An Inside Look Through Optical Diagnostics For Biomedical Applications, Liesl Krause, Ahmed Hassanein, Prasoon Diwakar

The Summer Undergraduate Research Fellowship (SURF) Symposium

An emerging technology for medical applications is cold atmospheric plasma (CAP). CAP is generated using various gasses in a “pen” to create room temperature plasma and then carry the effluents and species. Success has been shown when cold atmospheric plasma is applied to oncology treatments, accelerated wound healing, pathogen disinfection, and various material-changing effects. However, the mechanisms behind these effects are still speculative. This study uses multiple diagnostic techniques including fast photography, two wavelength emission spectroscopy and optical emission spectroscopy to characterize the plasma properties and eventually further test the plasma’s interaction with biological samples. The plume dynamics are observed …


Exploring The Effect Of Sample Properties On Spark-Induced Breakdown Spectroscopy, Michael J. Marino, Payson Dieffenbach, Liesl A. Krause, Prasoon Diwakar, Ahmed Hassanein Aug 2015

Exploring The Effect Of Sample Properties On Spark-Induced Breakdown Spectroscopy, Michael J. Marino, Payson Dieffenbach, Liesl A. Krause, Prasoon Diwakar, Ahmed Hassanein

The Summer Undergraduate Research Fellowship (SURF) Symposium

Optical emission spectroscopy techniques such as laser-induced breakdown spectroscopy (LIBS) and spark-induced breakdown spectroscopy (SIBS) provide portable and robust methods for elemental detection in real-time. Laser-produced emissions are then used for quantitative and qualitative analysis of a sample material with applications in explosives detection. For both techniques, the main obstacles have always been signal intensity, accuracy, and sensitivity of detection. The main advantage of the SIBS method is more safe operation, while still maintaining the portability of the technique. In this study, detailed characterization of spark induced plasma, analyte emission intensity, plasma temperature, electron density, and plasma persistence has been …