Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Engineering
Zno Nanowires For Advanced X-Ray Source Applications, Vance Scott Robinson
Zno Nanowires For Advanced X-Ray Source Applications, Vance Scott Robinson
Legacy Theses & Dissertations (2009 - 2024)
X-ray system technology trends tend towards simpler, smaller and more efficient devices. A broad range of applications are driving contemporary efforts in X-ray source miniaturization: Portable and/or remote nondestructive evaluation; High throughput protein crystallography, invasive radiotherapy; monitoring fluid flow and particulate generation in situ; and portable radiography devices for battle-front or large scale disaster triage scenarios. Most of the x-ray sources for these applications follow a top-down approach focused on improving portability, and reducing mass and/or size.
Field Emission Of Thermally Grown Carbon Nanostructures On Silicon Carbide, Jonathon M. Campbell
Field Emission Of Thermally Grown Carbon Nanostructures On Silicon Carbide, Jonathon M. Campbell
Theses and Dissertations
CNTs are known to be excellent field emitter due to their unique physical and electrical properties. Because of their semi-metallic nature, CNT do not suffer the thermal runaway found in metallic emitters, and their near one-dimension shape make them an ideal emission sources. CNTs growth by thermal decomposition of silicon carbide does not utilize a catalyst, therefore relatively defect free. One drawback to this method, however is that the CNT grow in a very dense carpet. This very dense CNT carpet comes under the affect of field emission screening effects which dampen the field emission. In this thesis, silicon carbide …
Characterization Of The Field Emission Properties Of Carbon Nanotubes Formed On Silicon Carbide Substrates By Surface Decomposition, Michael C. Pochet
Characterization Of The Field Emission Properties Of Carbon Nanotubes Formed On Silicon Carbide Substrates By Surface Decomposition, Michael C. Pochet
Theses and Dissertations
Dense arrays of vertically aligned carbon nanotubes (CNTs) form on the surface of silicon carbide wafers during high temperature anneals under moderate vacuum conditions. The novelty of this growth method is that the CNTs form without the aid of a metal catalyst, allowing for potentially impurity-free CNTs to form. In this study, CNT films were grown by the surface decomposition of silicon carbide substrates. The associated field emission characteristics were investigated to determine if films grown using this method possessed advantages over films grown using metal-catalyzed methods. The associated turn-on and threshold voltages, maximum current density, and emission current stability …