Interfacing the general 3D A- psi method with a thin sheet conductor model

A finite-element scheme for modeling 3-D eddy currents in general thick conductors and thin sheet conductors which can be in electrical contact is described. Volume eddy currents are modeled in terms of the magnetic scalar potential A and sheet eddy currents are modeled in terms of a scalar stream function T. Nonconducting regions are modeled using magnetic scalar potentials. The interface between the general thick conductors and the thin sheet conductors is described. The method has been implemented in the 2- and 3-D electromagnetics software package MEGA. The method yields good results for all cases tried in which the assumption of uniform distribution across the thickness of the sheet is reasonable. Results are presented for tokamak poloidal field coils.<
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