Self-Organized Stationary States of Tokamaks.

Information theory explanation of the fluctuation theorem, maximum entropy production and self- organized criticality in non-equilibrium stationary states

Jaynes’ information theory formalism of statistical mechanics is applied to the stationary states of open, non-equilibrium systems. First, it is shown that the probability distribution p of the underlying microscopic phase space trajectories over a time interval of length τ satisfies p ∝ exp(τσ /2kB) where σ is the time-averaged rate of entropy production of . Three consequences of this result ...

Non-equilibrium quasi-stationary states in a magnetized plasma

Non-equilibrium quasi-stationary states resulting from curvature driven interchange instabilities and driftwave instabilities in a low beta, weakly ionized, magnetized plasma are investigated in the context of laboratory experiments in a toroidal configuration. Analytic modelling, numerical simulations and experimental results are discussed with emphasis on identifying the unstable modes and un...

A Model Realization of Self-Organized Criticality for Plasma Confinement*

A model for plasma transport near marginal stability is presented. The model is based on subcritical resistive pressure-gradient-driven turbulence. Three-dimensional nonlinear calculations based on this model show effective transport for subcritical mean profiles. This model exhibits some of the characteristic properties of self-organized criticality. Perturbative transport techniques are used ...

Shared Information in Stationary States at Criticality

A statistical analysis of avalanching heat transport in stationary enhanced core confinement regimes

We present a statistical analysis of heat transport in stationary enhanced confinement regimes obtained from flux-driven gyrofluid simulations. The probability density functions of heat flux in improved confinement regimes, characterized by the Nusselt number, show significant deviation from Gaussian, with a markedly fat tail, implying the existence of heat avalanches. Two types of avalanching ...