Study of the Accuracy of the Numerical Plasma Boundary Reconstruction in the T-15MD Tokamak

The work presents a description and mathematical formulation of the D_Bound code designed to reconstruct the plasma boundary in a tokamak. This code is a modified version of the DINA-FIT code, which is part of the DINA plasma physics complex, and is designed for the T-15MD. The results of a numerical study of the accuracy of the plasma boundary reconstruction in the T-15MD tokamak using the D_Bound code are presented. The algorithm used has been validated for synthetic equilibrium magnetic configurations covering a wide range of the form of the plasma cross section. The influence of input data errors on the accuracy of the boundary reconstruction has been studied. It is shown that errors in determining currents in poloidal coils and an inductor have the greatest impact on the result. The stability of the method with respect to a decrease in the number of diagnostic sensors has been analyzed. The reconstructed positions of the plasma current centroid are compared with soft X-ray diagnostic data based on experimental pulses of the T-15MD campaign in the spring of 2025. Good agreement between the numerical results and the experiment is shown.