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It is shown that in an ideal coupled magnetofluid, the equilibrium magnetic (velocity) field is described by a two-parameter, double curl ({triangledown}{times}{triangledown}{times}) system of equations. The new system allows, among others, a novel, fully diamagnetic, pressure confining, minimum {vert_bar}B{vert_bar} configuration with velocity fields comparable (in appropriate units) to the magnetic fields. {copyright} {ital 1998} {ital The American Physical Society}

Null points in magnetic fields destroy the adiabatic invariants of charged particle motion, resulting in a chaotic motion. The mixing effect of the chaos produces efficient collisionless heating of electrons. The entropy production is represented by an effective resistance in a macroscopic description. This ``chaos-induced resistance'' enables plasma production at a low gas pressure suitable for ultrafine plasma etching.

A plasma flow induces mixing of magnetic flux, and the length scale cascades toward a small scale, resulting in amplification of the magnetic field. If the enhanced Lorentz force comes to dominate the dynamics, its backreaction should be taken into account. The magnetic force-free condition, which is amenable to slow motion of a strongly magnetized plasma, imposes a lower bound for the length scale. This bound avoids scale reduction down to the resistive regime, and extends the lifetime of the amplified magnetic field.

A magnetospheric configuration gives rise to various peculiar plasma phenomena that pose conundrums to astrophysical studies; at the same time, innovative technologies may draw on the rich physics of magnetospheric plasmas. We have created a "laboratory magnetosphere" with a levitating superconducting ring magnet. Here we show that charged particles (electrons) self-organize a stable vortex, in which particles diffuse inward to steepen the density gradient. The rotating electron cloud is sustained for more than 300 s. Because of its simple geometry and self-organization, this system will have wide applications in confining single- and multispecies charged particles.

We demonstrate that a purely ideal mechanism, originating in the space-time distortion caused by the demands of special relativity, can break the topological constraint (leading to helicity conservation) that would forbid the emergence of a magnetic field (a generalized vorticity) in an ideal nonrelativistic dynamics. The new mechanism, arising from the interaction between the inhomogeneous flow fields and inhomogeneous entropy, is universal and can provide a finite seed even for mildly relativistic flows.

A pure-electron plasma has been confined in a toroidal magnetic-surface configuration for as long as classical diffusion time due to neutral collisions. By controlling the potential of the internal conductor, long-term stable confinement of electrons has been achieved in a toroidal geometry.

Self-organization of an ordered structure occurs in a plasma under rather restrictive conditions. A new framework for a variational principle invokes a coercive form that results in a criterion for self-organizing relaxation of a two-fluid plasma. The constraints (constants of motion of the ideal model) are adjusted, through a weakly dissipative process, so that the relaxed state, under well-defined conditions, is a stable equilibrium independent of the direct effects of dissipation.

Magnetic null points act as scattering centers where particles describe chaotic orbits and the mixing effect increases the kinetic entropy. In an open system where convection of particles into/from the chaos region exists, the saturation of the entropy can be avoided, and continuous dissipation is achieved. The chaos-induced collisionless resistivity of ions enables fast magnetic reconnection. By matching the microscopic (kinetic process) and the macroscopic parameters of reconnection, we obtain a self-consistent model of the diffusion region.

When a super-Alfvenic electron beam propagates along an ambient magnetic field, the left-hand circularly polarized Alfven wave is Cherenkov-emitted (two stream instability). This instability results in a spontaneous conversion of the background plasma helicity to the wave helicity. The background helicity induces a frequency (energy) shift in the eigenmodes, which changes the critical velocity for Cherenkov emission, and it becomes possible for a sub-Alfvenic electron beam to excite a nonsingular Alfven mode.