Streamer dynamics in gases containing dust particles

Atmospheric pressure plasmas, and streamers in particular, sustained in air often encounter dust or aerosol particles having sizes of a few to tens of micrometres. The dynamics of streamers intersecting such particles are of interest due to their possible use for functionalizing the surfaces of the particles. Using a 2-dimensional plasma hydrodynamics model having an unstructured mesh, the consequences of dust particles on streamer dynamics were investigated while varying the particle size, shape and material properties. We found that while small dielectric particles (< tens of micrometres) are enveloped by the streamer, larger particles can intercept and reinitiate streamers. By increasing the permittivity and capacitance of the particles, streamer interception and re-initiation may also occur on smaller particles. The presence of multiple particles in the path of a streamer can increase the speed of the avalanche front due to synergistic polarization of the particles. 1