Equilibrium Configuration Reconstruction of Multipole Galatea Magnetic Trap Based on Magnetic Measurement

Abstract

Equilibrium reconstruction is an important basic work for the design and operation of a multipole Galatea magnetic trap device, and it is also a fundamental theoretical work for plasma equilibrium control. Based on the static equilibrium model of the multipole Galatea magnetic trap, an equilibrium reconstruction scheme based on solving the Grad–Shafranov equilibrium equation is proposed. In the proposed scheme, a plasma current density distribution model is established, and the combination of the Green function and the finite difference method is investigated to realize the fast solution to the Grad–Shafranov equilibrium equation. At the same time, the least-squares fitting method is employed, along with the magnetic probe measurement data, which realizes correction and iteration of the parameters of the plasma current density distribution model. Through simulation, the magnetic field distribution, plasma current density distribution, and plasma pressure distribution of multipole Galatea magnetic trap can be obtained, which confirms the effectiveness of the equilibrium reconstruction when compares with other experimental results. At the end of this paper, the influence of the magnetic field produced by the solenoid coil on the equilibrium configuration of plasma is studied.