Real-Time Equilibrium Reconstruction in a Tokamak

TL;DR

This paper presents a real-time method for reconstructing plasma equilibrium and current density in a Tokamak using a combination of measurements and advanced numerical algorithms.

Contribution

It introduces a novel real-time reconstruction technique combining finite element methods, fixed-point algorithms, and least-squares optimization for Tokamak plasma equilibrium.

Findings

Successful real-time reconstruction of plasma equilibrium.

Effective identification of non-linear sources in the Grad-Shafranov equation.

Integration of multiple measurement types for improved accuracy.

Abstract

This paper deals with the numerical reconstruction of the plasma current density in a Tokamak and of its equilibrium. The problem consists in the identification of a non-linear source in the 2D Grad-Shafranov equation, which governs the axisymmetric equilibrium of a plasma in a Tokamak. The experimental measurements that enable this identification are the magnetics on the vacuum vessel, but also polarimetric and interferometric measures on several chords, as well as motional Stark effect or pressure measurements. The reconstruction can be obtained in real-time using a finite element method, a non-linear fixed-point algorithm and a least-square optimization procedure.