The first structures were proto-voids formed in the primordial plasma when viscous and weak turbulence forces balanced gravitational forces at the scale of causal connection LH ≡ ct ≈ LSV ≡ (γν/ρG) 1/2 ≈ LST ≡ ε /(ρG) at time t ≈ 30 000 years (10 s) the age of the universe, with c the speed of light, γ ≈ 1/t the rate of strain, ν the kinematic viscosity, and LSV and LST Gibson’s 1996 viscous an...

A broad sample of fluid models for instability-driven plasma turbulence is surveyed to determine whether saturation involving damped eigenmodes requires special physics or is a common property of plasma turbulence driven by instability. Previous investigations have focused exclusively on turbulence in the core of tokamak discharges. The models surveyed here apply to a wide range of physical mec...

AIrstrati-Using plasma parameters from a typical stormtime ionospheric energy balance model, we have investigated the effects of plasma turbulence on the amoral magnetoplasma. The turbulence is assumed to be comprised of electrostatic ion cyclotron waves. These waves have been driven to a nonthermal level by a geomagnetic field-aligned, current-driven instability. The evolution of this instabil...

For forty years, plasma turbulence theory has been based on notions of ‘mixing length’, ‘diffusion’, and other ideas from mean field theory. However, there is now a plethora of evidence, from both simulations and experiments, that plasma turbulence is strongly intermittent and that transport is bursty, and composed of a multiplicity of "events" of differing scales. In this case, "predictive mod...

Three-dimensional fluid simulations are performed in a simple magnetized toroidal plasma, in which vertical and toroidal magnetic fields create helicoidal magnetic field lines that terminate on the torus vessel. The simulations are carried out in the three-dimensional flux tube that wraps around the torus and are able to describe both interchange and drift-wave dynamics. The presence of differe...

The physical mechanism of converting the kinetic energy turbulence to magnetic is known as a dynamo. Fluctuation dynamo amplifies fields at scales smaller than driving scale turbulence. We show that fluctuation in subsonic turbulent plasma similar supersonic case some aspects and very different others.

A new method to measure the internal magnetic field in a plasma, based on crosscorrelation of ordinary (O) mode and extraordinary (X) mode reflectometer signals originating from naturally occurring turbulence, is investigated. This method relies on identifying the Oand X-mode frequency pair (fo, fx) where cross-correlation is maximum. Maximum cross-correlation is found to occur at an X-mode fre...

Numerical simulation of plasma turbulence in the Large Plasma Device LAPD W. Gekelman, H. Pfister, Z. Lucky et al., Rev. Sci. Instrum. 62, 2875 1991 is presented. The model, implemented in the BOUndary Turbulence code M. Umansky, X. Xu, B. Dudson et al., Contrib. Plasma Phys. 180, 887 2009 , includes three-dimensional 3D collisional fluid equations for plasma density, electron parallel momentum...

Plasma shaping e¤ects, such as elongation, triangularity and Shafranov shift have long been considered an important ingredient in improving tokamak performance. It is known that the growth rate of ion temperature gradient (ITG) turbulence can be regulated by these shaping e¤ects and that the ITG turbulence level can also be regulated by zonal ‡ow. Moreover, recent numerical simulation shows tha...