Reconstruction of the Internal Magnetic Configuration of Two Merging Spherical Tokamak Plasmas by External Probe Measurement and MHD Simulation

A novel model to reconstruct the magnetic configuration inside the TS-6 spherical tokamak during the merging start-up is presented, utilizing the external magnetic measurements with a 2D Hall-MHD numerical simulation. A number of zero size numerical coils outside the measurement domain are responsible to produce the same poloidal flux values as the ones measured by the external probes located on the measurement boundary. This study shows that the reconstruction agrees with the measured one by 6% deviation during the merging. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.