Radiofrequency sheath rectification is a phenomenon relevant to the operation of Ion Cyclotron Range of Frequencies (ICRFs) actuators in tokamaks. Techniques to model the sheath rectification on 3D ICRF antenna geometries have only recently become available (Shiraiw et al 2023 Nucl. Fusion63 026024; Beers et al 2021 Phys. Plasmas28 093503). In this work, we apply the 'sheath-equivalent dielectric layer' technique, used previously only on linear devices (Beers et al 2021 Phys. Plasmas28 103508), in tokamak geometry, computing rectified sheath potentials on the WEST ICRF antenna. Advancing the state of the art in sheath rectification modeling, we compute the sheath potentials not just on the limiters, but also on the Faraday Screen bars. The calculations show a peak rectified DC potential of 300 V on the limiters and 500 V on the Faraday screen. Assuming a typical sputtering yield curve, the RF sheath rectification increases the sputtering yield from the limiters by a factor of 2.6 w.r.t. the sputtering due to the non-rectified thermal sheath.
This paper investigates radiofrequency (RF) sheath rectification, a phenomenon that affects the performance of Ion Cyclotron Range of Frequencies (ICRF) actuators in tokamaks. The researchers apply a technique called 'sheath-equivalent dielectric layer' to model the sheath rectification on the WEST ICRF antenna, including the Faraday screen bars. Their calculations show high rectified DC potentials, which can increase sputtering from the limiters and Faraday screen.