{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/25574"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/25574","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"The growth of density fluctuations in a finite sized inhomogeneous plasma","abstract":"The details of the absorption of electromagnetic radiation in a plasma are important to the physics of laser-fusion. We have studied the growth of density fluctuations in an inhomogeneous plasma because two mechanisms of absorption, anomalous absorption due to the growth of parametric instabilities and absorption by short wavelength density fluctuations, may be influenced by the growth of density fluctuations. An inhomogeneous bounded plasmas is modeled to represent a laser-fusion plasma; part of the plasma, which has been ablated from the main body of the plasma, is accounted for by adjustment of the boundary conditions on the density fluctuations. A system of hydrodynamic wave equations has been developed to study the growth of density fluctuations in an inhomogeneous bounded plasma. This formalism differs from established formalisms in that the spatial and temporal behaviors are separated by expanding the density fluctuations in eigenfunctions of the bounded inhomogeneous plasma. A variational technique has been developed to calculate these spatial eigenfunctions. Three separate approximations for the resulting temporal equations have been taken, which show that coupling between modes due to the beating of spatial eigenfunctions with the spatial profile of the incident electric field slows the growth of density fluctuations. Finally, the threshold electric field for the onset of instability is determined as a function of the size of the plasma, the wave-number of the density fluctuations and the density of the plasma.","abstract_html":"The details of the absorption of electromagnetic radiation in a plasma are important to the physics of laser-fusion. We have studied the growth of density fluctuations in an inhomogeneous plasma because two mechanisms of absorption, anomalous absorption due to the growth of parametric instabilities and absorption by short wavelength density fluctuations, may be influenced by the growth of density fluctuations. An inhomogeneous bounded plasmas is modeled to represent a laser-fusion plasma; part of the plasma, which has been ablated from the main body of the plasma, is accounted for by adjustment of the boundary conditions on the density fluctuations. A system of hydrodynamic wave equations has been developed to study the growth of density fluctuations in an inhomogeneous bounded plasma. This formalism differs from established formalisms in that the spatial and temporal behaviors are separated by expanding the density fluctuations in eigenfunctions of the bounded inhomogeneous plasma. A variational technique has been developed to calculate these spatial eigenfunctions. Three separate approximations for the resulting temporal equations have been taken, which show that coupling between modes due to the beating of spatial eigenfunctions with the spatial profile of the incident electric field slows the growth of density fluctuations. Finally, the threshold electric field for the onset of instability is determined as a function of the size of the plasma, the wave-number of the density fluctuations and the density of the plasma.","abstract_has_math":false,"creators":["Peterson, Robert Ross"],"institution":null,"degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Adler, F.T."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-06-29T16:02:04Z","date_published":"2011-06-29T16:02:04Z","updated_at":"2026-07-22T22:25:24Z","subjects":["density fluctuation","finite sized inhomogeneous plasma","electromagnetic radiation absorption","laser-fusion physics"],"languages":["en"],"rights":["1979 Robert Ross Peterson"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["360803"],"render_values":[{"text":"360803","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/25574","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Adler, F.T."]},{"key":"dc:creator","label":"Author","values":["Peterson, Robert Ross"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-06-29T16:02:04Z","10000-01-01","1979"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation / Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["density fluctuation","finite sized inhomogeneous plasma","electromagnetic radiation absorption","laser-fusion physics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["1979 Robert Ross Peterson"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["360803","http://hdl.handle.net/2142/25574"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The details of the absorption of electromagnetic radiation in a plasma are important to the physics of laser-fusion. We have studied the growth of density fluctuations in an inhomogeneous plasma because two mechanisms of absorption, anomalous absorption due to the growth of parametric instabilities and absorption by short wavelength density fluctuations, may be influenced by the growth of density fluctuations. An inhomogeneous bounded plasmas is modeled to represent a laser-fusion plasma; part of the plasma, which has been ablated from the main body of the plasma, is accounted for by adjustment of the boundary conditions on the density fluctuations. A system of hydrodynamic wave equations has been developed to study the growth of density fluctuations in an inhomogeneous bounded plasma. This formalism differs from established formalisms in that the spatial and temporal behaviors are separated by expanding the density fluctuations in eigenfunctions of the bounded inhomogeneous plasma. A variational technique has been developed to calculate these spatial eigenfunctions. Three separate approximations for the resulting temporal equations have been taken, which show that coupling between modes due to the beating of spatial eigenfunctions with the spatial profile of the incident electric field slows the growth of density fluctuations. Finally, the threshold electric field for the onset of instability is determined as a function of the size of the plasma, the wave-number of the density fluctuations and the density of the plasma.","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-29T16:02:04Z No. of bitstreams: 1 1979_peterson.pdf: 4849859 bytes, checksum: 43722d54e1a64215b99f541bbccddbf9 (MD5)","Made available in DSpace on 2011-06-29T16:02:04Z (GMT). No. of bitstreams: 1 1979_peterson.pdf: 4849859 bytes, checksum: 43722d54e1a64215b99f541bbccddbf9 (MD5) Previous issue date: 1979","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-06-29T16:02:04Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:32:22-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"]},{"key":"dc:title","label":"Title","values":["The growth of density fluctuations in a finite sized inhomogeneous plasma"]}]}],"canonical_facts":{"dc:contributor":["Adler, F.T."],"dc:creator":["Peterson, Robert Ross"],"dc:date":["2011-06-29T16:02:04Z","10000-01-01","1979"],"dc:description":["The details of the absorption of electromagnetic radiation in a plasma are important to the physics of laser-fusion. We have studied the growth of density fluctuations in an inhomogeneous plasma because two mechanisms of absorption, anomalous absorption due to the growth of parametric instabilities and absorption by short wavelength density fluctuations, may be influenced by the growth of density fluctuations. An inhomogeneous bounded plasmas is modeled to represent a laser-fusion plasma; part of the plasma, which has been ablated from the main body of the plasma, is accounted for by adjustment of the boundary conditions on the density fluctuations. A system of hydrodynamic wave equations has been developed to study the growth of density fluctuations in an inhomogeneous bounded plasma. This formalism differs from established formalisms in that the spatial and temporal behaviors are separated by expanding the density fluctuations in eigenfunctions of the bounded inhomogeneous plasma. A variational technique has been developed to calculate these spatial eigenfunctions. Three separate approximations for the resulting temporal equations have been taken, which show that coupling between modes due to the beating of spatial eigenfunctions with the spatial profile of the incident electric field slows the growth of density fluctuations. Finally, the threshold electric field for the onset of instability is determined as a function of the size of the plasma, the wave-number of the density fluctuations and the density of the plasma.","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-29T16:02:04Z No. of bitstreams: 1 1979_peterson.pdf: 4849859 bytes, checksum: 43722d54e1a64215b99f541bbccddbf9 (MD5)","Made available in DSpace on 2011-06-29T16:02:04Z (GMT). No. of bitstreams: 1 1979_peterson.pdf: 4849859 bytes, checksum: 43722d54e1a64215b99f541bbccddbf9 (MD5) Previous issue date: 1979","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-06-29T16:02:04Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:32:22-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"],"dc:identifier":["360803","http://hdl.handle.net/2142/25574"],"dc:language":["en"],"dc:rights":["1979 Robert Ross Peterson"],"dc:subject":["density fluctuation","finite sized inhomogeneous plasma","electromagnetic radiation absorption","laser-fusion physics"],"dc:title":["The growth of density fluctuations in a finite sized inhomogeneous plasma"],"dc:type":["Dissertation / Thesis","text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."]},"updated_at":"2026-07-22T22:25:24Z"}