Streamer Dynamics in a Media Containing Dust Particles

Summary form only given. The propagation of streamers in atmospheric pressure gases is of interest in plasma remediation of toxic gases, ozone production and functionalization of surfaces. The air (or other gases) in these non-pristine environments is often contaminated with particles or aerosols having sizes of 10s to 100s mum. These particles may have varying degrees of conductivity, from metallic to classically dielectric. The intersection of propagating streamers with particles not only results in charging of the particles but can also significantly perturb the streamer dynamics due to loss of charge, electric field enhancement and secondary processes. The consequences of dielectric and metal dust particles on streamer dynamics in air and other gases were computationally investigated. As a base case, the interaction of well developed streamers with isolated particles will be discussed. We found that the characteristic timescale on which the particle charges depends on the rate of electron attachment. Using a 2-dimensional plasma hydrodynamics model with unstructured meshes the consequences of random and ordered collections of dust particles were also investigated while varying the particle sizes and polarity of the voltage (e.g., positive and negative streamers). Changes in the properties of the streamers will be discussed. We found that the arrangement of the dust grains on streamer ignition can be significant.