Plasma equilibrium with barriers

The recently proposed concept of the transport barrier formation in a tokamak plasma as a bifurcation of the equilibrium state with a change in the toroidal magnetic field over the entire plasma column, including the plasma edge, is analyzed. The analysis is performed in the cylindrical approximation. It is shown that, in the framework of the discussed concept, all of the equilibrium solutions are continuous functions of the parameters involved, bifurcations are absent, and the result is determined by the model assumptions that are necessary in order to make the task self-contained. Removing even part of these restrictive assumptions can substantially change the result. Under typical conditions, the effect of the plasma rotation on the plasma equilibrium is negligibly small. Besides, from the viewpoint of the formal analysis of the force balance, the rotation does not facilitate but, in contrast, hampers the formation of a positive pressure jump.