Competition of Space charge effect and dielectric charging on multipactor saturation in a dielectric-loaded waveguide

In dielectric-loaded components, the buildup of multipactor charge leads to electron dispersion, driven by mutual repulsion among electron bunches and dielectric charging from secondary electron emission. Subsequently, electrons alternately and randomly induce single-sided multipactor (SSMP) and double-sided multipactor (DSMP) phenomena. A steady state is achieved once the electron bunches lose their resonant behavior. In this study, an electromagnetic particle-in-cell (EM-PIC) algorithm was developed to investigate the multipactor effect in dielectric-loaded components, considering both the space charge field and the electrostatic field induced by dielectric charging. Extensive simulations were conducted on one- and twosided dielectric-loaded parallel-plate waveguides, leading to insights into the multipactor saturation mechanisms driven by the emergence of space charge and electrostatic fields. The analysis specially delineated the interplay and competitive dynamics between the space charge field and electrostatic field in affecting resonant multipactor and hybrid-resonant multipactor behaviors.