A 1D1V Continuum Vlasov-Poisson Multipactor Analysis From Onset to Saturation Across the Entire First-Order Multipactor Regime

This report employs a Vlasov-Poisson model to elucidate fundamental electron phase-space mechanics of a multipactor discharge from onset to saturation. At the onset of multipactor, the electron phase-space is primarily defined by sharp features in both the physical space and energy space. With increasing electron density, space-charge effects lead to debunching of the swarm in phase-space. The temporal evolution of the electron energy distribution is studied across a single impact cycle. The average and peak-to-peak saturation values for the entire first-order multipactor regime are presented. Comparisons between the third- and fifth-order multipactors highlight the nuanced similarities and differences in the energy distribution of the multipacting system. The Vlasov-Poisson approach, which neglects collisions, is well suited for such analysis since the multipactor phenomenon occurs under near-vacuum collisionless conditions. It also overcomes difficulties associated with kinetic schemes that require adequately sampling all of the electron phase-space, including sparely populated regions, or special treatments to model strong growths in carrier densities.