MHD Equilibrium Reconstruction Using the Visible Light Tomographic Method with Laplacian Eigenfunction

Abstract

A tomographic method using tangential visible light is proposed for MHD equilibrium reconstruction via two processes. The first process is a tomographic method to estimate the last-closed-flux-surface (LCFS) in two-dimensional poloidal cross-section using a single tangential camera image. Applying the Laplacian eigenfunction series expansion and L₁ regularization, we can reconstruct the LCFS from relatively sparse and noisy observations. The second method is a free-boundary tokamak equilibrium calculation using the TASK/EQU code, in which we use the estimated plasma surface information as the constraints for the equilibrium calculation. As a result, we develop a new method for identifying equilibrium states using visible light information.