X-point heating, potentials, and temperature asymmetries in edge plasmas

Three-dimensional simulations of turbulence in the boundary plasma of a diverted tokamak indicate strongly localized heating and radial currents on closed flux surfaces in the vicinity of the X point, and over bllrstiness. We apply a long-mean-free path theory of particle and energy exchange between passing and potential-trapped electrons to show that these turbulent phenomena combined with natural fueling.asymmetries may lead to electron temperature, density and potential maxima in this region. Such maxima have been observed on the DIII-D tokamak