Characterization of breakdown and sustaining of a discharge in a gas bubble in water

Breakdown mechanism in water are not well understood. In the present study, we focus both on the ignition and propagation of the plasma in a bubble/water bi-phasic medium, as well as on the sustaining of DC plasmas in a gas bubble. Two geometries are studied : either the bubble is localized in a water filled capillary, or it is surrounded by water. Electrical study, fast CCD imaging, and time resolved emission spectroscopy were performed.