Diffusive particle and heat pinch effects in toroidal plasmas

A fully toroidal fluid description has been derived for electrostatic drift modes in plasmas with electron trapping. The system includes both a modified toroidal ion temperature gradient mode (ηi mode) and a new trapped electron mode. The transport, obtained both by quasi-linear theory and non-linear numerical simulations, shows several features that are in agreement with observations in tokamaks, such as particle or heat pinch effects. A general tendency for equilibration of the inhomogeneity scale lengths for the density and temperature is found.