On the continua in two-dimensional nonadiabatic magnetohydrodynamic spectra

The equations for the continuous subspectra of the linear magnetohydrodynamic (MHD) normal modes spectrum of two-dimensional (2D) plasmas are derived in general curvilinear coordinates, taking nonadiabatic effects in the energy equation into account. Previously published derivations of continuous sp...

Full description

Saved in:
Bibliographic Details
Published in:Physics of plasmas 2000-06, Vol.7 (6), p.2354-2365
Main Authors: De Ploey, A., Van der Linden, R. A. M., Beliën, A. J. C.
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The equations for the continuous subspectra of the linear magnetohydrodynamic (MHD) normal modes spectrum of two-dimensional (2D) plasmas are derived in general curvilinear coordinates, taking nonadiabatic effects in the energy equation into account. Previously published derivations of continuous spectra in the 2D ideal MHD case and in 1D nonadiabatic MHD are thus complemented with calculations for 2D nonadiabatic MHD spectra. The nonadiabatic MHD spectrum contains a thermal continuum in addition to the well-known Alfvén and slow continua. These thermal continuum modes are exponentially decaying or growing in time. The latter unstable modes are widely accepted as an explanation for the onset of marfes in tokamaks and the most favored hypothesis for prominence formation in the solar corona. A numerical code has been developed to calculate the continuum modes. An investigation of a typical ‘pre-MARFE’ (multifaceted asymmetric vadiation from the edge) equilibrium is presented.
ISSN:1070-664X
1089-7674
DOI:10.1063/1.874072