Transport barrier as a bifurcation of the equilibrium of a tokamak plasma

The phenomenon of the internal transport barrier in a tokamak plasma is interpreted as a bifurcation of the plasma equilibrium. An expression describing the change in the plasma pressure due to the buildup of the barrier is derived as a functional dependent on the parameters of the original plasma equilibrium and the plasma rotation velocity within the barrier. This expression is applied to a circular cross section tokamak, specifically, the T-10 device.