2015 Theses Doctoral
Local Regulation of Interchange Turbulence in a Dipole-Confined Plasma Torus using Current-Injection Feedback
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.
- Roberts_columbia_0054D_12646.pdf binary/octet-stream 12 MB Download File
- Academic Units
- Applied Physics and Applied Mathematics
- Thesis Advisors
- Mauel, Michael E.
- Ph.D., Columbia University