Spatially - and temporally- resolved investigation of discharge in water in pin-to-pin geometry

Summary form only given. In the recent years plasma in contact with liquids is receiving a wide attention due to many potential bio-medical and environmental applications. Usually such plasmas have very transient nature and understanding their kinetics and dynamics is very important. The easiest approach of conducting the investigation are non-disturbing optical diagnostics, such as fast-framing photography, Optical Emission Spectroscopy (OES) and various laser scattering techniques. In this work we report the results of the research study of a discharge in water in a pin-to-pin geometry. The discharge is ignited by application of high voltage pulse with amplitude of ~10 kV and duration of ~170 ns at full width at half maximum (FWHM). The cathode and the anode are made of stainless steel blades, fashioned in a pin form. The investigation performed includes fast framing imaging and Optical Emission Spectroscopy of Hydrogen Balmer lines. The fast framing imaging diagnostic shows the dynamics of the discharge development and the plasma formation. Spatial attention will be given in the presentation on the effect of nonequilibrium kinetics on the interpretation of the emission spectra for the determination of electron properties and gas temperatures.