{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/19211"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/19211","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Dust in plasmas: Microscopic and macroscopic modeling of particulate-contaminated glow discharges","abstract":"Glow discharges are often contaminated by particulates resulting from gas phase nucleation or sputtering of surfaces in contact with the plasma. If these particulates are sufficiently large, they will negatively charge and act as coulomb-like scattering centers for electrons. When this occurs, rate coefficients for high-threshold processes such as ionization may be reduced compared to those in pristine plasmas. If the contamination is nonuniform, then the resulting spatial irregularities in the rates of excitation may lead to plasma properties which are also nonuniform.","abstract_html":"Glow discharges are often contaminated by particulates resulting from gas phase nucleation or sputtering of surfaces in contact with the plasma. If these particulates are sufficiently large, they will negatively charge and act as coulomb-like scattering centers for electrons. When this occurs, rate coefficients for high-threshold processes such as ionization may be reduced compared to those in pristine plasmas. If the contamination is nonuniform, then the resulting spatial irregularities in the rates of excitation may lead to plasma properties which are also nonuniform.","abstract_has_math":false,"creators":["McCaughey, Michael Joseph, III"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Electrical Engineering","degree_department":null,"school":null,"contributors":["Kushner, Mark J."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T12:00:20Z","date_published":"2011-05-07T12:00:20Z","updated_at":"2026-07-22T22:25:12Z","subjects":["Engineering, Electronics and Electrical","Physics, Fluid and Plasma"],"languages":["eng"],"rights":["Copyright 1991 McCaughey, Michael Joseph, III"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9210912","(UMI)AAI9210912"],"render_values":[{"text":"AAI9210912","href":null,"code":true},{"text":"(UMI)AAI9210912","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/19211","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Kushner, Mark J."]},{"key":"dc:creator","label":"Author","values":["McCaughey, Michael Joseph, III"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T12:00:20Z","10000-01-01","1991"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering, Electronics and Electrical","Physics, Fluid and Plasma"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1991 McCaughey, Michael Joseph, III"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9210912","(UMI)AAI9210912","http://hdl.handle.net/2142/19211"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Glow discharges are often contaminated by particulates resulting from gas phase nucleation or sputtering of surfaces in contact with the plasma. If these particulates are sufficiently large, they will negatively charge and act as coulomb-like scattering centers for electrons. When this occurs, rate coefficients for high-threshold processes such as ionization may be reduced compared to those in pristine plasmas. If the contamination is nonuniform, then the resulting spatial irregularities in the rates of excitation may lead to plasma properties which are also nonuniform.","Two models have been developed to study the problem of dusty glow discharges: a Monte Carlo microscopic simulation of electron swarms in dusty plasmas, and a multi-dimensional continuum model of a typical glow discharge device. The microscopic model examines the plasma local to a dust particle and generates electron impact rate coefficients for use by the continuum model. The models allow parameterization of discharge system behavior as a function of dust size, density, and spatial distribution.","Results of the models for low-pressure argon and silane discharges indicate that electron impact rate coefficients, particularly for high-threshold processes such as ionization, are strongly reduced by the presence of dust. This effect increases with increasing dust densities; however, this effect is less pronounced in regions where E/N values are high. Under quasi-steady-state conditions, current flow and the subsequent excitation of the gas are channeled into regions of lower dust density, and these effects depend on the density, size and distribution of the dust. In low-pressure ($$ 10$\\sp5$cm$\\sp{-3}$Torr for 10 cm$\\sp{-3}$ $<$ N$\\sb{\\rm d} <$ 10$\\sp9$ cm$\\sp{-3}$ and P $<$ 50 Torr.","Made available in DSpace on 2011-05-07T12:00:20Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9210912.pdf: 4434854 bytes, checksum: 19653983346a8a917dddf35a6da4b9df (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:35:24Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:13:56-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Dust in plasmas: Microscopic and macroscopic modeling of particulate-contaminated glow discharges"]}]}],"canonical_facts":{"dc:contributor":["Kushner, Mark J."],"dc:creator":["McCaughey, Michael Joseph, III"],"dc:date":["2011-05-07T12:00:20Z","10000-01-01","1991"],"dc:description":["Glow discharges are often contaminated by particulates resulting from gas phase nucleation or sputtering of surfaces in contact with the plasma. If these particulates are sufficiently large, they will negatively charge and act as coulomb-like scattering centers for electrons. When this occurs, rate coefficients for high-threshold processes such as ionization may be reduced compared to those in pristine plasmas. If the contamination is nonuniform, then the resulting spatial irregularities in the rates of excitation may lead to plasma properties which are also nonuniform.","Two models have been developed to study the problem of dusty glow discharges: a Monte Carlo microscopic simulation of electron swarms in dusty plasmas, and a multi-dimensional continuum model of a typical glow discharge device. The microscopic model examines the plasma local to a dust particle and generates electron impact rate coefficients for use by the continuum model. The models allow parameterization of discharge system behavior as a function of dust size, density, and spatial distribution.","Results of the models for low-pressure argon and silane discharges indicate that electron impact rate coefficients, particularly for high-threshold processes such as ionization, are strongly reduced by the presence of dust. This effect increases with increasing dust densities; however, this effect is less pronounced in regions where E/N values are high. Under quasi-steady-state conditions, current flow and the subsequent excitation of the gas are channeled into regions of lower dust density, and these effects depend on the density, size and distribution of the dust. In low-pressure ($$ 10$\\sp5$cm$\\sp{-3}$Torr for 10 cm$\\sp{-3}$ $<$ N$\\sb{\\rm d} <$ 10$\\sp9$ cm$\\sp{-3}$ and P $<$ 50 Torr.","Made available in DSpace on 2011-05-07T12:00:20Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9210912.pdf: 4434854 bytes, checksum: 19653983346a8a917dddf35a6da4b9df (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:35:24Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:13:56-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9210912","(UMI)AAI9210912","http://hdl.handle.net/2142/19211"],"dc:language":["eng"],"dc:rights":["Copyright 1991 McCaughey, Michael Joseph, III"],"dc:subject":["Engineering, Electronics and Electrical","Physics, Fluid and Plasma"],"dc:title":["Dust in plasmas: Microscopic and macroscopic modeling of particulate-contaminated glow discharges"],"dc:type":["text"],"thesis:degree_discipline":["Electrical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:12Z"}