Electromagnetic analysis of a shielded gap for the RFX conducting shell

The numerical analyses carried out to assess the effectiveness of an electromagnetic shield are presented in the paper. The shield should-reduce the field errors on the magnetic configuration due to the gaps of a conducting shell of a nuclear fusion device, already in operation. The shield dimensions are limited by other components, so the actual effectiveness had to be accurately computed. The finite element method was used for 3-D eddy current analysis and the results were compared with measurements on the actual shell. The stray magnetic field in the plasma region with the shielded gap was 30% lower than with the unshielded gap.