Thermal processes in a streamer discharge in water

The propagation features of a streamer discharge in water have been investi gated. Based on the experimental data obtained in the study of water discha rges in a non-uniform electric field, the propagation of streamers is expla ined as the evaporation of water at the tip of the streamer and around it. The energy balance in the process of the streamer propagation is calculated for a sub-microsecond discharge in distilled water. It is shown that the e nergy released in the prebreakdown process is sufficient to evaporate the l iquid in the streamer channels. Similar velocity of the streamer propagatio n in both tap and distilled water substantiates negligible effect of ionic current density onto the streamer propagation process. These estimations ba sed on the experiment have relevance to the discussion on the nature of the dielectric breakdown of water.