{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/17044"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/17044","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"Investigation of Alfvén eigenmodes in Alcator C-Mod using active MHD spectroscopy","abstract":"Alfvén eigenmodes that exist in the shear Alfvén continuum of toroidal magnetic fusion devices may be important for the confinement of energetic particles, particularly fusion-born alpha particles in burning plasma experiments. Interaction between these energetic particles and weakly damped toroidal Alfvén eigenmodes (TAE's) may cause anomalous particle transport leading to incomplete thermalization and possible first wall damage. These consequences must be avoided in next step burning plasma devices and thus an investigation into the stability of TAE's in present machines un- der reactor-like conditions is essential. Measurement of the damping rate of TAE's will provide insight into this area of research. The investigation of TAE's on Alcator C-Mod is accomplished by employing the recently completed Active MHD Spectroscopy system. Antennas mounted inside the C-Mod vacuum vessel are driven by a high power amplifier in the TAE range of frequencies and excite modes inside the plasma. Magnetic fluctuation diagnostics provide the plasma response to this excitation. The damping rate is then calculated from the complex transfer function between the antenna current and plasma response signals.","abstract_html":"Alfvén eigenmodes that exist in the shear Alfvén continuum of toroidal magnetic fusion devices may be important for the confinement of energetic particles, particularly fusion-born alpha particles in burning plasma experiments. Interaction between these energetic particles and weakly damped toroidal Alfvén eigenmodes (TAE's) may cause anomalous particle transport leading to incomplete thermalization and possible first wall damage. These consequences must be avoided in next step burning plasma devices and thus an investigation into the stability of TAE's in present machines un- der reactor-like conditions is essential. Measurement of the damping rate of TAE's will provide insight into this area of research. The investigation of TAE's on Alcator C-Mod is accomplished by employing the recently completed Active MHD Spectroscopy system. Antennas mounted inside the C-Mod vacuum vessel are driven by a high power amplifier in the TAE range of frequencies and excite modes inside the plasma. Magnetic fluctuation diagnostics provide the plasma response to this excitation. The damping rate is then calculated from the complex transfer function between the antenna current and plasma response signals.","abstract_has_math":false,"creators":["Schmittdiel, D. (David), 1978-"],"institution":"Massachusetts Institute of Technology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Department of Nuclear Engineering","school":null,"contributors":[],"advisors":["Joseph A. Snipes."],"committee_chairs":[],"committee_members":[],"year":2003,"date_issued":"2003","date_published":"2003","updated_at":"2026-07-22T22:22:13Z","subjects":["Nuclear Engineering."],"languages":["eng"],"rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"rights_urls":["http://dspace.mit.edu/handle/1721.1/7582"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1721.1/17044","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Joseph A. Snipes."]},{"key":"dc:contributor.department","label":"Department","values":["Massachusetts Institute of Technology. Department of Nuclear Engineering","Massachusetts Institute of Technology. Department of Nuclear Science and Engineering"]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["Massachusetts Institute of Technology. Dept. of Nuclear Engineering."]},{"key":"dc:creator","label":"Author","values":["Schmittdiel, D. 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Antennas mounted inside the C-Mod vacuum vessel are driven by a high power amplifier in the TAE range of frequencies and excite modes inside the plasma. Magnetic fluctuation diagnostics provide the plasma response to this excitation. The damping rate is then calculated from the complex transfer function between the antenna current and plasma response signals."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["S.M."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Investigation of Alfvén eigenmodes in Alcator C-Mod using active MHD spectroscopy"]}]}],"canonical_facts":{"dc:contributor.advisor":["Joseph A. Snipes."],"dc:contributor.department":["Massachusetts Institute of Technology. Department of Nuclear Engineering","Massachusetts Institute of Technology. Department of Nuclear Science and Engineering"],"dc:contributor.other":["Massachusetts Institute of Technology. Dept. of Nuclear Engineering."],"dc:creator":["Schmittdiel, D. (David), 1978-"],"dc:date.accessioned":["2005-05-19T15:46:35Z"],"dc:date.available":["2005-05-19T15:46:35Z"],"dc:date.issued":["2003"],"dc:description":["Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2003.","Includes bibliographical references (119-121).","This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections."],"dc:description.abstract":["Alfvén eigenmodes that exist in the shear Alfvén continuum of toroidal magnetic fusion devices may be important for the confinement of energetic particles, particularly fusion-born alpha particles in burning plasma experiments. Interaction between these energetic particles and weakly damped toroidal Alfvén eigenmodes (TAE's) may cause anomalous particle transport leading to incomplete thermalization and possible first wall damage. These consequences must be avoided in next step burning plasma devices and thus an investigation into the stability of TAE's in present machines un- der reactor-like conditions is essential. Measurement of the damping rate of TAE's will provide insight into this area of research. The investigation of TAE's on Alcator C-Mod is accomplished by employing the recently completed Active MHD Spectroscopy system. Antennas mounted inside the C-Mod vacuum vessel are driven by a high power amplifier in the TAE range of frequencies and excite modes inside the plasma. Magnetic fluctuation diagnostics provide the plasma response to this excitation. The damping rate is then calculated from the complex transfer function between the antenna current and plasma response signals."],"dc:description.degree":["S.M."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/1721.1/17044"],"dc:language.iso":["eng"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"dc:rights.uri":["http://dspace.mit.edu/handle/1721.1/7582"],"dc:subject":["Nuclear Engineering."],"dc:title":["Investigation of Alfvén eigenmodes in Alcator C-Mod using active MHD spectroscopy"],"dc:type":["Thesis"]},"updated_at":"2026-07-22T22:22:13Z"}