Nonlinear analysis of magnetic reconnection using variational principle for collisionless plasma

Hirota, Makoto; Morrison, P. J.*

Magnetic reconnection in collisionless plasma is studied by applying a technique that utilizes the variational principle. Following the fact that the model of collisionless plasma constitutes a Hamiltonian system, the corresponding variational principle is formulated, where the displacement field of the fluid elements is the dynamical variable to be varied. If the potential energy of this variational principle decreases with respect to some displacement field, such the fluid motion turns out to grow with the release of free energy. A rather simple fluid motion is enough to prove the occurrence of spontaneous magnetic reconnection which, moreover, accelerates in the nonlinear phase.