Real-time plasma boundary reconstruction in the KSTAR tokamak using finite element method

A study is carried out on the real-time plasma shape identification in the KSTAR device. An improved form of the finite current element (FCE) method is utilized in this study. Results are shown that the plasma boundary can be reproduced in 7 mm accuracy for any plasma configuration in ideal cases without invoking measurement errors. A design guideline for magnetic diagnostics (MD) is established when the measurement signals are subject to Gaussian noise. It is found that the measurement errors in poloidal field (PF) coil currents have substantial influence on the determination of the plasma shape.