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Full-Text Articles in Physics
Control Of Charged Particle Dynamics And Electron Power Absorption Dynamics Utilizing Voltage Waveform Tailoring In Capacitively Driven Radio-Frequency Plasmas, Steven W. Brandt
Control Of Charged Particle Dynamics And Electron Power Absorption Dynamics Utilizing Voltage Waveform Tailoring In Capacitively Driven Radio-Frequency Plasmas, Steven W. Brandt
Graduate Theses, Dissertations, and Problem Reports
In this work, experimental measurements and analysis of numerical simulations are performed for capacitively coupled plasmas driven by tailored voltage waveforms under conditions which examine complicating factors present in industrial processes, including the influence of resonance effects, electronegative gases or gas mixtures, and plasma-surface interactions at a changing plasma-surface interface. Furthermore, the influence of different tailored voltage waveforms on the spatio-temporal electron power absorption, the generation of a DC self-bias, and on process relevant plasma parameters like ion energy distribution functions is investigated to provide a more complete understanding of the underlying fundamental plasma physics responsible for sustaining the discharge. …
The Role Of Bandgap In The Secondary Electron Emission Of Small Bandgap Semiconductors: Studies Of Graphitic Carbon, Neal E. Nickles
The Role Of Bandgap In The Secondary Electron Emission Of Small Bandgap Semiconductors: Studies Of Graphitic Carbon, Neal E. Nickles
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The question of whether the small bandgaps of semiconductors play a significant role in their secondary electron emission properties is investigated by studying evaporated graphitic amorphous carbon, which has a roughly 0.5 eV bandgap, in comparison with microcrystalline graphite, which has zero bandgap. The graphitic amorphous carbon is found to have a 30% increase in its maximum secondary electron yield over that of two microcrystalline graphite samples with comparable secondary electron yields: highly oriented pyrolytic graphite and colloidal graphite. The potentially confounding influence of the vacuum level has been isolated through the measurement of the photoelectron onset energy of the …
Measurement Of Angle-Resolved Secondary Electron Spectra, Robert Davies
Measurement Of Angle-Resolved Secondary Electron Spectra, Robert Davies
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Theoretical formulations of secondary electron emission over the past 20 years have exceeded the confirming ability of available measurements. An instrument has been developed and tested for the purpose of obtaining simultaneous angle- and energy-resolved (AER) secondary and backscattered electron measurements for energetic electrons incident on conducting surfaces. The instrument is found to be in good working order and the data quality found to be excellent for nearly all angles and energies investigated. A representative set of AER measurements has been acquired for 1500 eV electrons normally incident on polycrystalline gold. The data have been used to construct angle-resolved (AR) …
An Instrument For Experimental Secondary Electron Emission Investigations, With Application To The Spacecraft Charging Problem, Robert Davies
An Instrument For Experimental Secondary Electron Emission Investigations, With Application To The Spacecraft Charging Problem, Robert Davies
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Secondary electron emission (SEE) and incident-particle backscattering are important processes accompanying the impact of energetic electrons and ions on surfaces. The phenomena play a key role in the buildup of electrical charge on spacecraft surfaces. and are therefore of particular interest to scientists attempting to model spacecraft charging. In response to a demonstrated need for data, techniques for determining total secondary electron (SE) and backscatter (BS) yields S and n, and associated scattering-angle-resolved, scattering-energy-resolved, and simultaneous angle-energy-resolved yields have been developed. Further, an apparatus capable of making the necessary measurements for experimental determination of these quantities-for conducting materials in …