Separatrix shape measurement on field-reversed configuration plasmas.

In order to determine the separatrix shapes of field-reversed configuration plasmas with high accuracy, an iterative method that compares measured magnetic fluxes with the solution of the Grad-Shafranov equation is discussed in detail. Several suggestions for successfully treating the iterative method are given using numerical simulation and a mock-up experiment where conductors with three kinds of shape are inserted into the coil instead of the plasma. The iterative method is also applied to the field-reversed configuration plasma, and it is found that the separatrix shape has distinct ends and the axial location of the X point can be determined. [ABSTRACT FROM AUTHOR]