Hamiltonian magnetohydrodynamics: Lagrangian, Eulerian, and dynamically accessible stability-Examples with translation symmetry
Year: 2016
Authors: Andreussi T.; Morrison P. J.; Pegoraro F.
Autors Affiliation: SITAEL SpA; Univ Texas Austin; Univ Texas Austin; Dipartimento Fis E Fermi
Abstract: Because different constraints are imposed, stability conditions for dissipationless fluids and magnetofluids may take different forms when derived within the Lagrangian, Eulerian (energy-Casimir), or dynamically accessible frameworks. This is in particular the case when flows are present. These differences are explored explicitly by working out in detail two magnetohydrodynamic examples: convection against gravity in a stratified fluid and translationally invariant perturbations of a rotating magnetized plasma pinch. In this second example, we show in explicit form how to perform the time-dependent relabeling introduced in Andreussi et al. [Phys. Plasmas 20, 092104 (2013)] that makes it possible to reformulate Eulerian equilibria with flows as Lagrangian equilibria in the relabeled variables. The procedures detailed in the present article provide a paradigm that can be applied to more general plasma configurations and in addition extended to more general plasma descriptions where dissipation is absent. Published by AIP Publishing.
Journal/Review: PHYSICS OF PLASMAS
Volume: 23 (10) Pages from: to:
KeyWords: Hamiltonian plasma dynamicsDOI: 10.1063/1.4964900