Hydroxyl Radical Generation on Bubble Surface of Aqua-Plasma Discharge

The location of hydroxyl radical (OH
^*
) generation in aqua plasma is investigated with the images of vapor bubble discharge in a conductive electrolyte (saline). A comparison of the visible-and UV-ray data taken from the Na
^+*
and radical OH
^*
reveals that Na
^+*
is generated in both volume and surface of bubble while most of OH
^*
is observed at the vapor surface. This result implies that the steamer-type of aqua plasma was generated in the vapor bubble covered over a metal electrode tip, and the charged particles disperse along the surface of the vapor bubble.