Estimation of plasma elongation and position on noncircular tokamak TRIAM-1M

A method of estimating the plasma elongation and position using the magnetic field picked up by magnetic coils is described. The method is based on the approximate solution for the Grad-Shafranov equation including the effect of the eddy current on the resistive shell. When this method was applied to noncircular plasmas on TRIAM-1M, the analytical results were found to be in good agreement with the plasma shape observed by a TV camera and with the outermost magnetic surface obtained through the calculation of an MHD equilibrium code. This approach is suitable for the real-time analysis and feedback control of plasma shape in a noncircular tokamak. (author)