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dc.contributor.advisorJay Kesner and Darren T. Garnier.en_US
dc.contributor.authorBergmann, Ryan Men_US
dc.contributor.otherMassachusetts Institute of Technology. Dept. of Nuclear Science and Engineering.en_US
dc.date.accessioned2010-03-25T15:19:29Z
dc.date.available2010-03-25T15:19:29Z
dc.date.copyright2009en_US
dc.date.issued2009en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/53240
dc.descriptionThesis (S.M. and S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2009.en_US
dc.descriptionCataloged from PDF version of thesis.en_US
dc.descriptionIncludes bibliographical references (p. 95-96).en_US
dc.description.abstractA vertically adjustable electrostatic probe array was made to observe the previously seen low-frequency angular oscillations in LDX and identify if they are related to computationally expected convective cells. The array rests one meter from the centerline and measures edge fluctuations at field lines near the separatrix. It spans ninety degrees and has 24 probes mounted on it for total probe tip separation of 6.8cm. Bispectral analysis of the fluctuations show that that an inverse cascade of energy is present at times in LDX. The cascade transfers energy from small spatial scale structures to large scale structures. The wavenumber spectrum is xc k-1.4 to cx k-25 at high wavenumbers, which encompasses the inverse energy cascade regime of c k-5/3. The plasma also has a linear dispersion relation which gives a phase velocity of 2-16 k. This phase velocity is inversely correlated with neutral gas pressure in the vessel. The velocity also has a local maximum at 5 pTorr which is the pressure that produces maximum plasma density. The radial E x B drift velocities are observed to have a mean near zero, which indicates a closed structure like a convective cell. The instantaneous radial drift velocities are on the order of the ion sound speed, which is 35 km/s.en_US
dc.description.statementofresponsibilityby Ryan M. Bergmann.en_US
dc.format.extentxi, 96 p.en_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsM.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.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582en_US
dc.subjectNuclear Science and Engineering.en_US
dc.titleCharacterization of low-frequency electric potential oscillations near the edge of a plasma confined by a levitated magnetic dipoleen_US
dc.typeThesisen_US
dc.description.degreeS.M.and S.B.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Dept. of Nuclear Science and Engineering.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Nuclear Science and Engineering
dc.identifier.oclc535773556en_US


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