Transport analysis based on K-ɛ anomalous transport model

Abstract

A K‐e anomalous transport model for resistive interchange turbulence is presented and applied to the transport analysis of ECH plasmas in Heliotron E. In this model, the turbulent kinetic energy K≡1/2〈v2〉 and its viscous dissipation rate e characterize the local turbulence and the anomalous transport coefficient is given by D∼Kw/e, which has some nonlocal properties not included in the conventional expressions since their temporal and spatial variations are determined by taking into account the transport of the turbulent energy itself. In the case of the homogeneous turbulence where the anomalous transport may be described in terms of the local plasma parameters, the dimensional analysis applied to our model yields the two types of local parameter expressions of the anomalous diffusivity in the high and low collisional cases. We find a familiar diffusivity for the resistive interchange turbulence derived in the high collisional case and we have another one similar to the gyro‐reduced Bohm (GRB) diffusivi...