  Surface flashover across insulator in vacuum is a destructive plasma
discharge which undermines the behaviors of a range of applications in
electrical engineering, particle physics, space engineering, etc. This
phenomenon is widely modeled by the particle-in-cell (PIC) simulation, here the
continuum and kinetic simulation method is first proposed and implemented as an
alternative solution for flashover modeling, aiming for the prevention of the
unfavorable particle noises in PIC models. The 1D2V (one dimension in space,
two dimensions in velocity) kinetic simulation model is constructed. Modeling
setup, physical assumptions, and simulation algorithm are presented in detail,
and a comparison with the well-known secondary electron emission avalanche
(SEEA) analytical expression and existing PIC simulation is made. Obtained
kinetic simulation results are consistent with the analytical prediction, and
feature noise-free data of surface charge density as well as particle fluxes of
primary and secondary electrons. Discrepancies between the two simulation
models and analytical predictions are explained. The code is convenient for
updating to include additional physical processes, and possible implementations
of outgassing and extra plasma species for final breakdown stage are discussed.
The proposed continuum and kinetic approach is expected to inspire future
flashover modeling studies for the understanding and mitigation.
