Control of gradient-driven instabilities using shear Alfv\'en beat waves
Abstract
A new technique for manipulation and control of gradient-driven instabilities through nonlinear interaction with Alfv\'en waves in a laboratory plasma is presented. A narrow field-aligned density depletion is created in the Large Plasma Device (LAPD), resulting in coherent unstable fluctuations on the periphery of the depletion. Two independent kinetic Alfv\'en waves are launched along the depletion at separate frequencies, creating a nonlinear beat-wave response at or near the frequency of the original instability. When the beat-wave has sufficient amplitude, the original unstable mode is suppressed, leaving only the beat-wave response at a different frequency, generally at lower amplitude.
Cite
@article{arxiv.1005.0647,
title = {Control of gradient-driven instabilities using shear Alfv\'en beat waves},
author = {D. W. Auerbach and T. A. Carter and S. Vincena and P. Popovich},
journal= {arXiv preprint arXiv:1005.0647},
year = {2015}
}
Comments
Submitted for Publication in Physical Review Letters. Revision 2 reflects changes suggested by referees for PRL submission. One figure removed, several major changes to another figure, and a number of major and minor changes to the text