Distributed Control of Coupled Inhomogeneous Diffusion in Tokamak Plasmas

This article proposes novel distributed control methods for the coupled dynamics of the safety factor and electron temperature profiles in tokamaks. The feedback design is based on an infinite-dimensional setting using the Lyapunov analysis for partial differential equations. The coupled dynamics is modeled by two 1-D linearized resistive diffusion equations. We first propose a combined control of both dynamics based on stability analysis. A composite control is then synthesized using a singular perturbation theory where the fast component of the electron temperature is decoupled from the slow component induced by the magnetic field dynamics. Both control methods are evaluated using the RApid Plasma Transport simulatOR simulator and applied to the International Thermonuclear Experimental Reactor tokamak device. The distributed control is performed using antennas operated at electron cyclotron frequency.