Theoretical study of the structure of the electric field in helical toroidal plasmas by the use of an anomalous transport model

A set of transport equations is analysed, including the bifurcation of theelectric field. The structure of the electric field is studied by the use of atheoretical model for anomalous transport diffusivities.A steep gradient of the electric field is obtained at the electric domain.The suppression of anomalous transport diffusivity is studied in the presence of a strong shear of the electric field. The hard transition between the multiple ambipolar solutions is examined in the structure of the radial electric field. The soft transition (without the multiple ambipolar electric field) is also obtained.