Tokamak Free-Boundary Plasma Equilibrium Computations in Presence of Non-Linear Materials

We consider the axisymmetric formulation of the equilibrium problem for a hot plasma in a tokamak. We adopt a non-overlapping mortar element approach, that couples C0 piece wise linear Lagrange finite elements in a region that does not contain the plasma and C1 piece-wise cubic reduced Hsieh-Clough-Tocher finite elements elsewhere, to approximate the magnetic flux field on a triangular mesh of the poloidal tokamak section. The inclusion of ferromagnetic parts is simplified by assuming that they fit within the axisymmetric modeling and a new formulation of the Newton algorithm for the problem solution is stated, both in the static and quasi-static evolution cases.

Automated summary

This paper investigates the axisymmetric equilibrium problem of a hot plasma in a tokamak. A non-overlapping mortar element approach is adopted, which couples C0 piece-wise linear Lagrange finite elements in a region without plasma and C1 piece-wise cubic reduced Hsieh-Clough-Tocher finite elements elsewhere, to approximate the magnetic flux field on a triangular mesh of the poloidal tokamak section. The inclusion of ferromagnetic parts is simplified by assuming their axisymmetric fit, and a new formulation of the Newton algorithm for problem solution is stated for both static and quasi-static evolution cases.