Investigation of a two-dimensional microscale RF sheath model*

Radio frequency (RF) sheaths are of fundamental importance in understanding boundary ICRF interactions in fusion devices. In this work the 1D RF sheath microscale model investigated previously [J. R. Myra and D. A. D'Ippolito, Phys. Plasmas 22, 062507 (2015)] is generalized to 2D using a numerical nonlinear fluid model.  Two-dimensional effects are important near points where the magnetic field is tangent to the surface, or where the local surface radius of curvature is comparable to the sheath width, as might occur due to surface irregularities.  Numerical results from the 2D model and their interpretation will be presented with the end goal of improving the fidelity of the RF sheath impedance boundary condition.