Lab Report On Astrophysical Plasma Essay
5230CvMagnetohydrodynamics (including electron magnetohydrodynamics)
5272+vLaboratory studies of space- and astrophysical-plasma processes
There has been significant recent work on Vlasov-Maxwell (VM) equilibria that are consistent with nonlinear force-free1–8 and “nearly force-free”9 magnetic fields in Cartesian geometry. Therein, force-free refers to a magnetic field for which the associated current density is exactly parallel, which is the definition we shall also use
j×B=0.These works consider one-dimensional (1D) collisionless current sheets, with Refs. 1–8 specifically calculating VM equilibrium distribution functions (DFs) that are self-consistent with a given specific magnetic field configuration. A natural question to consider is whether it is also possible to find self-consistent force-free (or nearly force-free) VM equilibria for other geometries, in particular, cylindrical geometry. In this paper, we shall present particular VM equilibria for 1D magnetic fields which are nearly force-free in cylindrical geometry, i.e., flux tubes/ropes.
Two of the archetypal field configurations in cylindrical geometry are the z-Pinch (with axial current and azimuthal magnetic field), a classical example of which is the Bennett Pinch;10 and the θ-Pinch (azimuthal current and axial magnetic field). Consideration of…