In-liquid plasma electrode, in-liquid plasma generating apparatus and in-liquid plasma generating method

Abstract

An in-liquid plasma electrode according to the present invention is an in-liquid plasma electrode for generating plasma in a liquid and has an electrically conductive member having an electric discharge end surface in contact with the liquid, and an electrically insulating member covering an outer periphery of the conductive member at least except the electric discharge end surface. Preferably, d and x satisfy −2d≦x≦2d, where d is a length of a minor axis of the cross section when a conductive end portion of the electrically conductive member having the electric discharge end surface has an approximately circular cross section, or d is a length of a short side of the cross section when the conductive end portion has an approximately rectangular cross section, and x is a distance from a reference plane to a plane containing the electric discharge end surface when the reference plane is an end surface of the electrically insulating member that is approximately parallel with the electric discharge end surface. Owing to this construction, it is possible to provide an in-liquid plasma electrode which can simply generate plasma in a wide variety of liquids including a conductive liquid such as water and alcohol, and furthermore an in-liquid plasma generating apparatus having this electrode, and an in-liquid plasma generating method using this electrode.