Thermally driven turbulence and transport in a sheared system

Abstract

Results from a novel theory of radiatively enhanced tokamak edge turbulent transport are presented. A serious restriction on the impurity radiation drive is identified. In particular, due to a lack of pressure balance near a rational surface, the condensation effect does not survive. Consequently, the thermal instability drive is the only impurity radiation instability which remains. Our analysis consists of a theoretical calculation for the thermally driven drift-rippling mode model (\ensuremath{\varphi}\ifmmode \tilde{}\else \~{}\fi{},n\ifmmode \tilde{}\else \~{}\fi{},T\ifmmode \tilde{}\else \~{}\fi{},v${\mathrm{\ifmmode \tilde{}\else \~{}\fi{}}}_{\mathrm{\ensuremath{\parallel}}}$). We present calculations of the edge fluctuations and the resultant transport coefficients versus radius.