On the effects of nonuniform zonal flow in the resistive-drift plasma

초록

We study the impact of the zonal-vorticity gradient (zonal-flow curvature) V '' by enforcing sinusoidally-varying zonal flow in the highly-adiabatic resistive-drift plasma. Initial small disturbance becomes linearly unstable and the fluctuating electric potential phi and the density n are found localized radially near the peak of positive V along the electron diamagnetic drift, irrespective of the amplitude of V. During the nonlinear phase of saturation, the turbulence sustains the localized state depending on the maximum positive V ''. Where V < 0, the cross phase delta between phi and n is negative if the (positive) renormalized electron diamagnetic drift is slower than the (negative) curvature-induced advecting velocity, which is proportional to V ''. Where delta < 0, the fluctuations are not driven excited and the turbulence level is low. As a result, the fluctuations are mostly localized around where V > 0 and maximum.

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