J. Plasma Fusion Res. SERIES, Vol.4 (2001) 5tg_523 Nonlinear stationary structures in a Drfit wave Turbulence Modulated by Zonal Flows

We investigate nonlinear stationary structures in a system of coupled equations describing drift wave turbulence and associated self-consistent zonal flows. The short scale drift wave turbulence is described by a kinetic wave equation for the action density of drift waves, whereas the longer scale zonal flows are described by a dynamic equation for the toroidally and poloidally symmetric component of the potential. A variety ofradially propagating coherent structures such as nonlinear periodic wave trains, solitons and shocks in the modulation envelope are shown to be possible. Keywords: drift wave, zonal flow, coherent structure, stationary structure, turbulenc