Validation of ERMES 20.0 finite element code for JET A2 antennas coupling studies

This study presents the validation of the finite element code ERMES 20.0, benchmarked against the well-established method-of-moments code TOPICA. The simulations focus on Ion Cyclotron Resonance Heating (ICRH) coupling for the JET A2 antennas. Validation is performed by comparing two key metrics: the scattering parameter matrix (S-matrix) and the electric field distribution in front of the antenna. These parameters are critical for assessing ICRH antenna-plasma coupling efficiency and understanding interactions with plasma-facing components. The results show a strong agreement between ERMES 20.0 and TOPICA, confirming the accuracy and reliability of the finite element approach. This comparative analysis highlights the capability of ERMES 20.0 to support advanced modeling of sheath rectification and wave–edge plasma interactions, which are central phenomena in ICRH system design and optimization.