Implementation of sheath effects into TOPICA

Recent experiments have shown that anomalous power losses and hot spots can occur due to the acceleration of ions into the antenna walls by RF sheath potentials. Parametric studies show that temperature increases on the ICRF antennas are proportional to the local plasma density and to the applied RF voltage, and decay exponentially with increasing antenna-plasma distance. At present, realistic ICRF antenna codes do not include sheath effects. TOPICA combines accurate 3D modeling of ICRF antennas with a realistic 1D hot plasma model. Its typical output is the scattering matrix and the currents on the conductors. The goal of the present work is to adapt TOPICA such that it can accurately predict detrimental sheath effects such as hot spots on the ntenna.