Non-intrinsic ambipolar diffusion in turbulence theory

Ambipolar flow in a turbulent plasma is investigated by combining a WKB treatment of the waves with a turbulent collision operator resulting from either quasi-linear theory or certain renormalized turbulence theories. If the wave momentum has a flow from outgoing waves, then particle diffusion is not intrinsically ambipolar, and the time variation of the electric-potential profile is determined by the turbulent spectrum. However, in most cases of practical interest, as in the drift-wave problem, this effect is small; and, in steady state, equal rates of stochastic diffusion are predicted for electrons and ions