Simple on-line indication of the Doublet III shaping parameters from magnetic measurements

A flux loop method has been developed to indicate the elongation and triangularity of a plasma cross section immediately after a shot. The method incorporates the appropriate flux loop signals and produces the value of the flux loop elongation and triangularity. Suitable flux loop combinations were selected according ESTHER code prediction; their quantitative correspondence was decided by the fitting of the experimental data. The shaping parameter indication by this method shows good agreement with the equilibrium analysis. This method can be incorporated into the feedback control system of the plasma cross section