An Etymological Dictionary of Astronomy and Astrophysics

In → magnetohydrodynamic (MHD) treatment of → plasmas, that component of the → Lorentz force which is directed toward the centre of curvature of the → magnetic field lines and thus acts to straighten out the field lines.

The Lorentz force can be decomposed into two components orthogonal to the magnetic field:

j× B = (B . ∇) B / μ₀

• ∇ (B² / 2μ₀),

where j is the → current density, μ₀ is the → magnetic permeability of free space, and B is the → magnetic flux density. The left side term is the Lorentz force, the first term on the right side is the magnetic tension and the second term the → magnetic pressure.

See also: → magnetic; → tension.