Identification of a free boundary arising in a magneto-hydrodynamics system

Abstract

We study the free boundary problem to identify the plasma region in a stationary tokamak machine using the magnetic flux function. Uniqueness has been proved and the free boundary has been explicitly computed in the case where the domain is an n-dimensional ball. We also derive an energy distribution identity which is applicable to identify the location of the free boundary for more general domains in two-dimensional space.