In this paper we use the SSWICH-SW software to calculate the (nonlinear) plasma potential near the ASDEX Upgrade 3-strap antenna for various operating parameters, and compare it with the (linear) parallel electric field strength and the (linear) RF potential. It is believed that the plasma potential is the cause of ion sputtering and additional heat loads on the antenna, and that the parallel electric field strength (as calculated by linear codes without sheath boundary conditions) is a good proxy for the plasma potential, and our results confirm the latter.
Reduction of RF-sheaths potentials by compensation or suppression of parallel RF currents on ICRF antennas