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Nuclear Engineering

Doctoral Dissertations

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Fusion

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Full-Text Articles in Engineering

Determination Of Near-Sol Carbon Impurity Content Due To Divertor Target Leakage Using Carbon-13 Tracers Via Methane Injection On The Diii-D Tokamak, Jonah David Duran Dec 2022

Determination Of Near-Sol Carbon Impurity Content Due To Divertor Target Leakage Using Carbon-13 Tracers Via Methane Injection On The Diii-D Tokamak, Jonah David Duran

Doctoral Dissertations

Experiments with outer strike point injection of isotopically enriched methane (13CD­4) in DIII-D L-mode discharges have demonstrated the ability to infer near scrape-off-layer (SOL) impurity density profiles based on: far-SOL collector probe (CP) measurements; a stable isotopic mixing model; and SOL impurity transport modelling. This work enables one of the first in-depth investigations on the source and transport of SOL impurities which could hinder performance of future fusion devices. Modelling by DIVIMP and 3DLIM of 13C SOL evolution is consistent with diagnostic observations and indicates that the buildup of injected impurities on plasma-facing surfaces must …


First Development And Demonstration Of Fiber Optic Bolometer, Seungsup Lee Dec 2022

First Development And Demonstration Of Fiber Optic Bolometer, Seungsup Lee

Doctoral Dissertations

The fiber optic bolometer (FOB) was demonstrated observing a fusion plasma for the first time, and 2D fiber optic bolometer was developed and demonstrated to have high spatial resolution. The FOB is a novel type of a bolometer that is theoretically immune to EMI. A bolometer that is a sensor that measure the power of the incoming electromagnetic radiation. The most common bolometer used in fusion research is a resistive bolometer that utilize resistors in an electrical circuit. Due to high electromagnetic interferences (EMI) in fusion environment, noise can be a serious problem in determining accurate plasma radiation. The demonstration …


Demonstrating The Use Of Multiple Experimental Techniques To Investigate Helium-Hydrogen Synergies In Tungsten, Wendy A. Garcia Aug 2022

Demonstrating The Use Of Multiple Experimental Techniques To Investigate Helium-Hydrogen Synergies In Tungsten, Wendy A. Garcia

Doctoral Dissertations

Polycrystalline W sample discs measuring 6 mm by 0.5 mm have been exposed to a low-energy (70 eV) He plasma using a low flux ( ) [1.3 times 10 to the 17 Helium per meter squared per second] ECR source located at the University of Tennessee in Dr. Donovan's laboratory. The samples were exposed to three different He fluences ( ) [5 times 10 to the 19 Helium per meter squared, 5 times 10 to the 20 Helium per meter squared, 5 times 10 to the 21 Helium per meter squared] at surface temperatures of ~300 K, 600 K and …