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Stephen J. Wukitch and Ronald R. Parker. Parisot, Alexandre, 1979- Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science 2006-03-24T18:18:58Z 2006-03-24T18:18:58Z 2004 2004 http://hdl.handle.net/1721.1/30095 55676137 Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004. Includes bibliographical references (p. 125-127). In Ion Cyclotron Radiofrequency Heating (ICRH) for tokamaks, fast variations of the antenna loading impedance limit flexible and robust high-power operations. In this thesis, novel solutions for real-time matching and reduction of these variations are investigated and studied for implementation on the Alcator C-Mod tokamak. Load tolerant prematching networks are reviewed and a prototype configuration for E-antenna is proposed. By maintaining low voltage standing wave ratio in the network for a wide range of loading conditions, it could allow robust high power operations without the need of fast matching. However, typical conditions could create current imbalance effects ; the performance of the system could be degraded and the phasing between the antenna affected, with side-effects on the overall behavior of the antenna in plasma. Another possible option for real-time matching uses ferrite loaded transmission lines, whose electrical length could be varied over timescales as fast as a few milliseconds. A potential ferrite material is identified and experimentally characterized in a small-scale low power experiment. This leads to design guidelines for a high power ferrite phase shifter and a fast-matching network using such tuners. by Alexandre Parisot. S.M. 127 p. 8673165 bytes 8672974 bytes application/pdf application/pdf eng Massachusetts Institute of Technology 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. http://dspace.mit.edu/handle/1721.1/7582 Electrical Engineering and Computer Science. Design of an ICRF fast matching system on Alcator C-Mod Ion cyclotron radiofrequency heating fast matching system on Alcator C-Mod Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="1efb5bfd-822d-4e85-8c16-24182fe1b530"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Design of an ICRF fast matching system on Alcator C-Mod</Title> <Subtitle>Ion cyclotron radiofrequency heating fast matching system on Alcator C-Mod</Subtitle> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2004</PublicationDate> <Authors> <Author> <DisplayName>Parisot, Alexandre, 1979-</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Electrical Engineering and Computer Science.</Keyword> <Abstract>In Ion Cyclotron Radiofrequency Heating (ICRH) for tokamaks, fast variations of the antenna loading impedance limit flexible and robust high-power operations. In this thesis, novel solutions for real-time matching and reduction of these variations are investigated and studied for implementation on the Alcator C-Mod tokamak. Load tolerant prematching networks are reviewed and a prototype configuration for E-antenna is proposed. By maintaining low voltage standing wave ratio in the network for a wide range of loading conditions, it could allow robust high power operations without the need of fast matching. However, typical conditions could create current imbalance effects ; the performance of the system could be degraded and the phasing between the antenna affected, with side-effects on the overall behavior of the antenna in plasma. Another possible option for real-time matching uses ferrite loaded transmission lines, whose electrical length could be varied over timescales as fast as a few milliseconds. A potential ferrite material is identified and experimentally characterized in a small-scale low power experiment. This leads to design guidelines for a high power ferrite phase shifter and a fast-matching network using such tuners.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>