Numerical Analysis on Multipactor Effects in Coaxial Cables via Particle-in-Cell Algorithm

We present a numerical analysis on multipactor effects in coaxial cables using an electromagnetic particle-in-cell (EM-PIC) algorithm on unstructured grids. The analysis combines a 2.5-D axisymmetric EM-PIC algorithm and the Furman-Pivi probabilistic model for the realistic description of secondary electron emission (SEE) process. Employing a local and explicit finite-element time-domain (FETD) scheme, the present algorithm yields an energy- and charge-conservation from first principles on unstructured grids. We numerically investigate single- and double-sided multipactor effects confirming that the former originates from the higher-order multipactors (in parallel plates) in conjunction with ponderomotive (inhomogeneous) forces. This analysis can be instrumental in devising multipactor mitigation techniques.