Observation of multilayer-structured discharge in plasma ionization breakdown
De‐Qi Wen, Peng Zhang, Janez Krek, Yangyang Fu, John Verboncoeur
Abstract
In this Letter, a multilayer-structured discharge (MSD) is reported in multipactor-coexisting plasma ionization breakdown by fully kinetic particle-in-cell simulations. The observed multilayer structure is originated by the response of ions to an electric field. It is found that the electron diffusion and multipactor discharge near the surface produce two opposite electric fields toward and away from the dielectric surface, respectively. Thus, the ions form a locally high density profile, which is followed by electron density. The lighter electrons diffuse away from the peak more quickly than the ions, resulting in an ambipolar field toward the bulk plasma region, which drives the ion density peak to propagate toward the bulk plasma. Such a process is periodically repeated, and, finally, a MSD is formed.