Temporal development of pulsed streamer discharges in water

Summary form only given, as follows. Temporal development of pulsed streamer discharges in water and the post-discharge phenomena are presented. The streamer discharges were generated using a needle to wire electrode immersed in 5 mm thick water vessel. Positive polarity pulsed voltages with 500 ns duration and 50 kV amplitude were given to the needle electrode. Either deionized water (1 M/spl Omega/cm) or saline water (1 k/spl Omega/cm) was used as the discharge medium. Both time resolved laser Schheren method and visible emission photography utilize an intensified CCD camera with an acquisition time of 15 ns, which enable to observe the temporal development of streamer discharges.