MHD equilibrium: Difference between revisions

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== Flux surfaces ==
== Flux surfaces ==


An important concept in this context is the ''flux surface'', which is a surface such that ''B'' is everywhere perpendicular to its normal.
An important concept in this context is the [[Flux surface|flux surface]], which is a surface such that ''B'' is everywhere perpendicular to its normal.
The force balance equation implies that ''p'' is constant along any field line (since ∇''p'' is perpendicular to ''B''), which is an expression of the underlying assumption that transport along the magnetic field lines is much faster than transport perpendicular to it.
The force balance equation implies that ''p'' is constant along any field line (since ∇''p'' is perpendicular to ''B''), which is an expression of the underlying assumption that transport along the magnetic field lines is much faster than transport perpendicular to it.
The force balance equation also implies that the surface ''p'' = constant is a flux surface (assuming flux surfaces exist).
The force balance equation also implies that the surface ''p'' = constant is a flux surface (assuming flux surfaces exist).