Transition of radial electric field in helical systems

Transition of radial electric field is investigated in helical plasmas for the given plasma fluxes. The density and temperature gradients are simultan eously determined together with radial electric field. The electric field s hows a nature of bifurcation, if an anomalous particle transport exists in addition to the neoclassical particle flux. Based on the Maxwell's construc tion with respect to the work-done, the critical condition for the bifurcat ion is obtained. The existence of bifurcation is not affected by the anomal ous energy flux. The gradients are found to be subject to bifurcation at hi gh plasma fluxes regime. The transition to a better confinement is predicte d. The presence of hard transition of the gradient and electric field indic ates the existence of the electric domain interface, across which the disco ntinuous change of gradient takes place.