Predictions of ICRF induced sheaths and sputtering in the LAPD experiment

A major goal of ICRF research is to design an antenna that minimizes impurity production while coupling substantial power to the plasma. The LArge Plasma Device (LAPD) at UCLA provides a flexible and accessible platform for validation studies of ICRF wave core propagation and interaction with plasma facing components. LAPD has a 100 kW single strap ICRF antenna and has plasmas with densities of and temperatures of that is similar to the edge of a tokamak or stellerator. We apply the Petra-M RF module to ICRF scenarios in LAPD including fast and slow wave propagation. We will show validation studies on wave propagation measurements and discuss model results for slow wave mode conversion to the ion plasma wave and fast wave incident on a conducting plate. The conducting plate study will also include calculations of RF sheath potentials and estimates of sputtering yields for different plate materials under a helium plasma.