ISSN:
1089-7674
Source:
AIP Digital Archive
Topics:
Physics
Notes:
By means of a global mode analysis of ideal magnetohydrodynamic (MHD) modes for Mercier-unstable equilibria in a planar axis L=2/M=10 heliotron/torsatron system with an inherently large Shafranov shift, the conjecture for global mode in Mercier-unstable equilibria from local mode analysis [N. Nakajima, Phys. Plasmas 3, 4556 (1996)] has been confirmed and the properties of pressure-driven modes inherent to such three-dimensional systems have been clarified. The Mercier-unstable equilibria are categorized into toroidicity-dominant and helicity-dominant Mercier-unstable equilibria. In the toroidicity-dominant Mercier-unstable equilibria, the pressure-driven modes change from interchange modes for low toroidal mode numbers n〈M, to tokamak-like ballooning modes for moderate toroidal mode numbers n∼M, and finally to ballooning modes purely inherent to three-dimensional systems for fairly high toroidal mode numbers n(very-much-greater-than)M. In the helicity-dominant Mercier-unstable equilibria, the pressure-driven modes change from interchange modes for n〈M or n∼M, directly to ballooning modes purely inherent to three-dimensional systems for n(very-much-greater-than)M. © 1999 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.873410
