Transport Model of Boundary Plasma and Evaluation of Transport Coefficients

Abstract

Using particle and energy conservation laws, particle and thermal diffusivities for both ions and electrons perpendicular to the flux surface at the scrape-off layer (SOL) in tokamaks were evaluated just outside the magnetic separatrix, where the source term due to ionization, charge exchange loss and the effect of the temperature gradient is exactly included. The diffusivities are expressed in terms of e-folding length of the density, temperatures and Mach number and its absolute values were evaluated using the data obtained by the electrostatic probe in SOL plasma in JFT-2M tokamak.