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Active Control of Alfvén Eigenmodes by Externally Applied 3D Magnetic Perturbations
J Gonzalez-Martin1,2, M Garcia-Munoz3, J Galdon-Quiroga3
1Department of Mechanical Engineering and Manufacturing, University of Seville, Camino de los Descubrimientos s/n, 41092 Seville, Spain.
Physical Review Letters
|February 10, 2023
Summary
Researchers controlled Alfvén eigenmodes in tokamak plasma using external 3D fields. This method redistributes fast ions, offering insights for managing instabilities in future fusion reactors.
Area of Science:
- Plasma Physics
- Fusion Energy
- Magnetohydrodynamics
Background:
- Alfvén eigenmodes are plasma instabilities that can affect fusion reactor performance.
- Controlling these instabilities is crucial for future burning plasma devices.
- External perturbations are explored as a novel control method.
Purpose of the Study:
- To experimentally suppress and excite Alfvén eigenmodes using 3D perturbative fields.
- To investigate the underlying mechanisms of fast-ion redistribution and mode control.
- To assess the potential application in future fusion energy systems.
Main Methods:
- Experimental application of 3D perturbative fields with varying spatial spectra in tokamak plasma.
- Hybrid kinetic-magnetohydrodynamic (MHD) simulations to analyze plasma behavior.
- Analysis of fast-ion redistribution and transport mechanisms.
Main Results:
- Successful experimental suppression and excitation of Alfvén eigenmodes.
- Demonstration that 3D fields induce fast-ion redistribution via an edge resonant transport layer.
- Identification of phase-space gradients modification as the key to mode control.
Conclusions:
- External 3D fields provide a viable method for controlling Alfvén eigenmodes.
- Understanding fast-ion transport is critical for managing plasma instabilities.
- This research aids in the development of stable burning plasma fusion reactors.
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