2006 Volume 1 Pages 012
In fluid equations describing edge plasma transport, the fluctuating flow causing anomalous transport is frequently interpreted as noise. The transport which is generated by the noise is represented as diffusion. In the present paper, the validity of the anomalous diffusion model of the fluctuating flow, i.e., Γa = -Da • ∇v, is examined from the viewpoint of a stochastic approach to modeling, where v is a velocity field and Da is a tensor of an anomalous diffusion coefficient. The examination is carried out on the presupposition that the validity of the diffusion model itself is not strongly related to details of the edge plasma. If the diffusion model is derived directly from the fundamental properties of the fluctuating flow, then the model is understood to be not merely an approximate description of the anomalous transport but to be inherent in the transport. However, it is found that because the noise given from the fluctuating flow is essentially bounded, the transport modeling is not justied.
