Academic Commons

Theses Doctoral

Local Regulation of Interchange Turbulence in a Dipole-Confined Plasma Torus using Current-Injection Feedback

Roberts, Thomas Maximillian

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.


  • thumnail for Roberts_columbia_0054D_12646.pdf Roberts_columbia_0054D_12646.pdf binary/octet-stream 12 MB Download File

More About This Work

Academic Units
Applied Physics and Applied Mathematics
Thesis Advisors
Mauel, Michael E.
Ph.D., Columbia University
Published Here
April 28, 2015
Academic Commons provides global access to research and scholarship produced at Columbia University, Barnard College, Teachers College, Union Theological Seminary and Jewish Theological Seminary. Academic Commons is managed by the Columbia University Libraries.