Local ideal magnetohydrodynamic stability of a quasihelically symmetric stellarator
- Torsatron/Stellarator Laboratory, University of Wisconsin---Madison, Madison, Wisconsin 53706-1691 (United States)
- Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, Ecole Polytechnique Federale de Lausanne, CRPP-PPB, CH-1015 Lausanne (Switzerland)
The ideal magnetohydrodynamic stability with respect to localized ballooning modes and the Mercier criterion of a quasihelically symmetric stellarator configuration is investigated. Configurations with an enhanced magnetic mirror and a deeper magnetic well that can be achieved by energizing a set of auxiliary coils have also been analyzed. In all cases, the Mercier criterion imposes a slightly stricter {beta} limit than the ballooning modes. Using relatively broad pressure profiles, the Mercier criterion yields {beta}=0.4{percent} for the standard configuration, {beta}=0.3{percent} for the high mirror configuration and {beta}=1.3{percent} for the deep well configuration. The comparable ballooning limits are {beta}=0.7{percent}, {beta}=0.6{percent}, and {beta}=1.66{percent} for the standard, high mirror, and deep well configurations, respectively. With a more peaked pressure profile, ballooning instabilities near the center of the plasma and Mercier modes near the edge of the plasma limit the performance of the standard configuration at {beta}{approx_equal}0.8{percent}. {copyright} {ital 1996 American Institute of Physics.}
- DOE Contract Number:
- FG02-93ER54222
- OSTI ID:
- 383788
- Journal Information:
- Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 3; ISSN PHPAEN; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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