On the basis of statistical theory of strong turbulence in inhomogeneous plasmas

A statistical model for plasma turbulence is examined by employing a basis from the Mori method [H. Mori: Prog. Theor. Phys. 33 (1965) 423]. The Mori method provides a base for the existence of the separation of the memory function from fluctuating force in the nonlinear dynamical equations. An analytic model for the turbulent damping coefficient is derived by use of the Green's function. The model formula takes a non-Markovian form, representing the property of the time-reversibility of the basic equation. A recurrence formula is derived. The continued fraction form is also derived. A formula of the eddy-damping rate is derived. A rigorous relation which is derived by the Mori method is discussed, and is compared to the modelling. This comparison explains a nature of approximation in the modelling.