RF Ionization and Multipaction Breakdown Prediction for High Power Antennas

This paper describes system-level simulations for high-power RF antennas from full-wave electromagnetics to RF breakdown in a harsh environment (under vacuum as well as high pressure) for arbitrary 3D structures. Full-wave electromagnetic simulations can be performed in HFSS using the modal or terminal solution, the time-domain simulation then takes over to predict the onset of corona discharge and multipaction breakdown. The entire simulation can be executed in a single run for antenna analysis and the prediction of RF breakdown. The accuracy and robustness of the simulation have been guaranteed through the FEM unstructured mesh. Particle-in-cell simulation for tracking multipaction electrons in an unstructured FEM mesh is a key success. A comprehensive visualization user interface helps to explain the detailed physics.