2026-09-18T19:48:01Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/412752023-02-26T02:47:50Zcom_1721.1_7582com_1721.1_7581col_1721.1_131022
Peter J. Catto and Kim Molvig.
Xiao, Yong
Massachusetts Institute of Technology. Dept. of Nuclear Science and Engineering.
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
2008-04-23T14:38:21Z
2008-04-23T14:38:21Z
2006
http://hdl.handle.net/1721.1/41275
213479574
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2006.
"June 2006."
Includes bibliographical references (p. 127-129).
Sheared zonal flow is known to be the predominant saturation mechanism of plasma turbulence. Rosenbluth and Hinton(R-H) have shown that the zonal flow level is inversely proportional to the plasma radial polarizability due to magnetic drift departure from a flux surface. In another calculation, Hinton and Rosenbluth (H-R) considered the weakly collisional case in the banana regime and calculated the neoclassical polarization and associated zonal flow damping in the high frequency and low frequency limits. The work presented here extends R-H's calculation in several aspects. We calculate the neoclassical polarization for arbitrary radial wavelength zonal flows so that finite ion banana width and ion gyroradius are retained. We also add plasma shape effects into the R-H collisionless calculation and find the influence of elongation and triangularity on neoclassical polarization and zonal flow damping. In addition, we extend the H-R collisional calculation using an exact eigenfunction expansion of the collision operator to calculate neoclassical polarization for the entire range of frequencies. A semi-analytical fit of the exact results is obtained that gives the polarization to within 15% and allows the collisional zonal flow damping rate to be evaluated for arbitrary collisionality.
by Yong Xiao.
Ph.D.
129 p.
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
Nuclear Science and Engineering.
Neoclassical polarization
Thesis
application/pdf
false
Publication
unknown
unknown
<Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="93494b49-d30e-4c6a-a86f-fa98ac2856e0">
<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>Neoclassical polarization</Title>
<PublishedIn>
<Publication>
</Publication>
</PublishedIn>
<PublicationDate>2006</PublicationDate>
<Authors>
<Author>
<DisplayName>Xiao, Yong</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>Nuclear Science and Engineering.</Keyword>
<Abstract>Sheared zonal flow is known to be the predominant saturation mechanism of plasma turbulence. Rosenbluth and Hinton(R-H) have shown that the zonal flow level is inversely proportional to the plasma radial polarizability due to magnetic drift departure from a flux surface. In another calculation, Hinton and Rosenbluth (H-R) considered the weakly collisional case in the banana regime and calculated the neoclassical polarization and associated zonal flow damping in the high frequency and low frequency limits. The work presented here extends R-H's calculation in several aspects. We calculate the neoclassical polarization for arbitrary radial wavelength zonal flows so that finite ion banana width and ion gyroradius are retained. We also add plasma shape effects into the R-H collisionless calculation and find the influence of elongation and triangularity on neoclassical polarization and zonal flow damping. In addition, we extend the H-R collisional calculation using an exact eigenfunction expansion of the collision operator to calculate neoclassical polarization for the entire range of frequencies. A semi-analytical fit of the exact results is obtained that gives the polarization to within 15% and allows the collisional zonal flow damping rate to be evaluated for arbitrary collisionality.</Abstract>
<Access xmlns="http://purl.org/coar/access_right"
>
</Access>
</Publication>