Statistical Theory of Subcritically-Excited Strong Turbulence in Inhomogenous plasmas
A statistical mechanics description is extended for a self-sustained inhomogenous turbulence, including the effects of thermal fluctuations. Interchange mode in the presence of inhomogenous magnetic field, which reveals a subcritically-excited strong turbulence, is considered as a collective mode. A Langevin equation is formulated for a test mode, in which the coherent interactions with thermal fluctuations are kept as a collisional drag and the incoherent ones are considered to be thermal noise: The coherent nonlinear interactions are kept as a renormalized turbulent drag, and the incoherent ones are considered to be random self-noise. Both thermal and turbulent excitations are thus included. The solutions of the stationary turbulent state are obtained, provided that both noises are statistically independent. The analysis for the fluctuation level, decorrelation rate, and the correlation functions clearly shows the connection between a mode which is excited by thermal fluctuations and the one being subcritically self-excited. The level is expressed as nonlinear functions of nonequilibrium parameter.
Bibliographic Reference: Article: IPP 111/240, (1999)
Record Number: 199910829 / Last updated on: 1999-06-07
Original language: en
Available languages: en