Equilibrium poloidal field distributions in reversed-field-pinch toroidal discharges

Abstract

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Equilibrium poloidal-field distributions in reversed-field-pinch toroidal discharges

“…An axisymmetric Grad-Shafranov code [4][5][6][7] was used to assess the accuracy of the analytic formulae. The equilibrium calculations were run for ideal-MHD conditions in toroidal geometry with RFP profiles [1]. For comparison purposes, as is normally done in practice, the input quantities %[ and j3 p are obtained directly from a cylindrical model without toroidal corrections.…”

“…The use of neutral injection on a variety of stellarator experiments [1,2] means that stellarator equilibria should be calculated allowing for anisotropic pressure. Here a scalar-pressure calculation [3,4] is generalized to allow for a pressure tensor: ?…”

“…Here a scalar-pressure calculation [3,4] is generalized to allow for a pressure tensor: ? = P i T+(P,-P i )nn (1) where n is a unit vector along the magnetic field 5.…”

“…In designing a poloidal-field system, an expeditious approach is to use the approximate Shafranov formulae to compute the poloidal field at the shell for a desired plasma equilibrium. From this field, the required winding distribution is determined [1]. Since, however, the Shafranov formulae use expansions in e, the inverse toroidal aspect ratio, questions arise regarding their accuracy as a function of plasma beta, plasma inductance, and toroidal aspect ratio.…”