State diagrams of Tokamaks and state transitions

Publisher Website
Google Scholar
Abstract
In a simple one-fluid cylindrical model of transport and of dissipative effects, the family of the magnetic states of the Tokamak which correspond to a vanishing entropy production in the confinement region (according to the configurational magnetic entropy introduced in previous work) is characterized by a define relation or 'state equation' involving the relevant parameters of the discharge. The author investigates how the entropy production changes when the current density profile is rearranged by a perturbation which conserves the poloidal magnetic flux. It is shown that for a sufficiently short time interval, that is to say t2<< tau E tau s where tau E is the energy confinement time and tau s is the resistive time, neighbouring bifurcating equilibria exist which can be reached with a flux-conserving transition and with increase of the magnetic entropy. The family of these new states can also be characterized by a state equation involving the relevant discharge parameters.

This publication has 9 references indexed in Scilit: