Subcritical mirror structures in an anisotropic plasma
E. A. Kuznetsov+*×, T. Passot, V. P. Ruban×, P. L. Sulem
+Lebedev Physical Institute of the RAS, 119991 Moscow, Russia
*Space Research Institute of the RAS, 117997 Moscow, Russia
×Landau Institute for Theoretical Physics of the RAS, 119334 Moscow, Russia
Universitéde Nice-Sophia Antipolis, CNRS, Observatoire de la Côte d'Azur, PB 4229, 06304 Nice Cedex 4, France
Based on Grad-Shafranov-like equations, a gyrotropic plasma where the
pressures in the static regime are only functions of the amplitude of the
local magnetic field is shown to be amenable to a variational principle
with a free energy density given by the parallel tension.
This approach is used to demonstrate that small-amplitude static holes
constructed slightly below the mirror instability threshold identify with
of KPII (Kadomtsev-Petviashvili) equation and turn out to be unstable. It is also shown that
regularizing effects such as finite
Larmor radius corrections cannot be ignored in the description of
large-amplitude mirror structures.