Temporal evolution of drift-type modes in plasma flows with strong time-dependent velocity shear

Full text: New approach to the investigations of time-varying plasma flows is developed. The linear and weak nonlinear theory of the temporal evolution of drift-type modes in strong shear flows, extended to include time variation of the flow velocity with time scales which may be comparable with turbulent time scales, is considered. Analysis is performed in the time domain without spectral decomposition in time. The explicit results are presented for Hasegava-Mima equation and drift-interchange modes. The kinetic theory for drift and ion cyclotron modes in time-dependent shear flow is developed. This theory accounted for the Larmor orbit squeezing and wave pattern stretching in non-stationary shear flow. The application of the obtained results to the improved confinement regimes and to the experiments with time-depended biasing are discussed. (author)