Generation of Coherent Structures in Electron Magnetohydrodynamics

A statistical equilibrium model of coherent structures in magnetohydrodynamics

A statistical equilibrium theory is developed which characterizes the large-scale coherent structures that emerge during the course of the evolution of an ideal two-dimensional magnetofluid. Macrostates are defined to be local joint probability distributions, or Young measures, on the values of the fluctuating magnetic field and velocity field at each point in the spatial domain. The most proba...

Maximum entropy states and coherent structures in magnetohydrodynamics

We review a recently developed model of coherent structures in twodimensional magnetohydrodynamic turbulence. This model is based upon a constrained maximum entropy principle: Most probable states are determined as maximizers of entropy subject to constraints imposed by the conservation of energy, cross-helicity, and flux under the evolution of an ideal two-dimensional magnetofluid. Predictions...

Free Electron Generation of Xuv Coherent Light

Magnetic field generation by coherent turbulence structures

It is thought that the small-scale magnetic fields observed in accretion discs, galaxies and galactic clusters are generated by a dynamo process in which the turbulent plasma amplifies small initial magnetic fluctuations. Numerical simulations of turbulence have revealed that turbulence consists of filamentlike vortex structures superimposed on an incoherent background, which carry a considerab...

Nonlinear electron magnetohydrodynamics physics. III. Electron energization

Wave-particle interactions of low-frequency whistler modes with wave magnetic fields exceeding the ambient field are investigated experimentally. These highly nonlinear modes are excited with magnetic loop antennas in a large magnetized afterglow plasma. While the nonlinear wave properties are described elsewhere, the present paper focuses on the modification of the electron distribution functi...