Woltjer's theorem and the force-free magnetic field stability problem.
Abstract
Woltjer's theorem on the energy minimum of the force-free field (rotH→ = αH→) in a closed system provided α = const and helicity is conserved, is shown to be in agreement with the results of stability investigations by a conventional strain energy method. The theorem becomes invalid in a resistive medium while the helicity changes due to reconnections of lines of force. The topological relaxation results in a force-free configuration without peculiar magnetic surfaces. For cylindrical geometry of the field such a configuration is a uniformly twisted magnetic flux rope.
- Publication:
-
Byulletin Solnechnye Dannye Akademie Nauk SSSR
- Pub Date:
- 1985
- Bibcode:
- 1985BSolD1985...55S
- Keywords:
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- Magnetohydrodynamics:Stability