Surface wave launchers to produce plasma columns and means for producing plasma of different shapes

A device for producing plasma of given shape and size, comprising:

• a surface wave launcher that can be energized, formed with an opening;
• a vessel having an inner surface, completely made of dielectric material and containing a gas that can be ionized, said vessel including:
• (a) a surface wave launcher receiving portion inserted in said opening and conforming thereto, said opening comprising means for transferring energy from said surface wave launcher to said gas in the receiving portion to ionize the latter gas;
• (b) a usable portion having a shape and size corresponding to the shape and size of the plasma to be produced, said receiving and usable portions of the vessel being substantially different from each other in cross-sectional shape or size;
• and
• (c) a smooth, tapered transition portion for interconnecting the said receiving and usable portions;
• whereby, in operation, ionization of the gas in the receiving portion produces plasma and a surface wave propagating on the inner surface of the vessel from the said receiving portion to said usable portion through the said transition portion to thereby create in the said usable portion the plasma having the shape and size of the usable portion.