Mode conversion in cold low-density plasma with a sheared magnetic field
Abstract
A theory is proposed that describes mutual conversion of two electromagnetic modes in cold low-density plasma, specifically, in the high-frequency limit where the ion response is negligible. In contrast to the classic (Landau--Zener-type) theory of mode conversion, the region of resonant coupling in low-density plasma is not necessarily narrow, so the coupling matrix cannot be approximated with its first-order Taylor expansion; also, the initial conditions are set up differently. For the case of strong magnetic shear, a simple method is identified for preparing a two-mode wave such that it transforms into a single-mode wave upon entering high-density plasma. The theory can be used for reduced modeling of wave-power input in fusion plasmas. In particular, applications are envisioned in stellarator research, where the mutual conversion of two electromagnetic modes near the plasma edge is a known issue.
Cite
@article{arxiv.1709.02841,
title = {Mode conversion in cold low-density plasma with a sheared magnetic field},
author = {I. Y. Dodin and D. E. Ruiz and S. Kubo},
journal= {arXiv preprint arXiv:1709.02841},
year = {2018}
}