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 resulted 30% lower than with the unshielded gap