1.Institut für Theoretische Physik IV, Fakult?t für Physik und Astronomie, Ruhr-Universit?t Bochum, 44780 Bochum, Germany,DE;2.Department of Plasma Physics, Ume? University, 90187 Ume?, Sweden,SE
Abstract:
Phase coherent interactions between drift waves and zonal flows are considered. For this purpose, mode coupling equations
are derived by using a two-fluid model and the guiding center drifts. The equations are then Fourier analyzed to deduce the
nonlinear dispersion relations. The latter depict the excitation of zonal flows due to the ponderomotive forces of drift waves.
The flute-like zonal flows with insignificant density fluctuations have faster growth rates than those which have a finite
wavelength along the magnetic field direction. The relevance of our investigation to drift wave driven zonal flows in computer
simulations and laboratory plasmas is discussed.
Received 5 April 2002 Published online 28 June 2002