Local Regulation of Interchange Turbulence in a Dipole-Confined Plasma Torus using Current-Injection Feedback
By: Thomas Maximillian Roberts
Publisher: [publisher not identified]
Published: 2015
Place of publication: [New York, N.Y.?]
Language: eng
Description: Turbulence in plasma confined by a magnetic dipole is dominated by interchange fluctuations with complex dynamics and short spatial coherence. We report the first use of local current-collection feedback to modify, amplify, and suppress these fluctuations. The spatial extent of turbulence regulation is limited to a correlation length near the collector. Changing the gain and phase of collection results in power either extracted from or injected into the turbulence. This mechanism is analogous to the magnetospheric-ionospheric coupling by field-aligned currents. The measured plasma response shows some agreement with calculations of the linear response of global interchange-like MHD and entropy modes to current-collection feedback.
Notes: Department: Applied Physics and Applied Mathematics.

Thesis advisor: Michael E. Mauel.

Thesis (Ph.D.)--Columbia University, 2015.