Statistical Theory of Subcritically-Excited Strong Turbulence in Inhomogenous Plasmas
A statizitical description is developed for a self-sustained subcritical turbulence in inhomogenous plasmas. Interchange mode in the presence of inhomogenous magnetic field, which reveals a submarginal strong turbulence, is considered. Nonlinear dispersion relation is extended to a Langevin equation for a dressed test mode, in which nonlinear interactions are kept as renormalized drag and random self noize. Based upon the assumption that the random noize has a faster time scale, the solutions are obtained for the fluctuation level, decorrelation rate, auto- and cross-correlations function and spectrum. They are expressed as nonlinear functions of non-equilibrium parameters like gradient. Extended fluctuation-dissipation theorum is described as statistical relations. Then the Langevin equation is reformulated into a Fokker-Planck equation of the probability distribution function. The steady state probability function is solved. Imposing the constraint of the self-noize, the power-law distribution with respect to the fluctuation amplitude is obtained in the tail of the distribution function.
Bibliographic Reference: Article: Statistical Theory of Subcritically-Excited Strong Turbulence in Inhomogenous Plasmas, 1998, 1-50
Record Number: 199910430 / Last updated on: 1999-03-19
Original language: en
Available languages: en