Eddy current experiments with closely placed solid boxes simulating a next step fusion device

Eddy current experiments with closely placed solid boxes driven by a coil alternative current were carried out. The experiment was to designed to identify approaches to the problems about: (1) computing accuracy of the eddy current calculation with thin plate approximation; and (2) modeling baselines for a computational study of eddy currents in a super conducting (SC) fusion device. The following conclusions were drawn from experimental data and their comparison with eddy current analyses: (1) the skin effect is a major cause of computational error; (2) if the error due to the skin effect cannot be ignored, the double shell model calculates accurate eddy currents; (3) the mesh size with a narrow gap should be small enough (for example smaller than five times the gap width) so as not to cause additional error. The Finite Element Method (FEM) model for the eddy current computation is well modeled using these conclusions.