Patent ID: 6224836
Filing Date: 2001-05-01
Classification: H05H

Abstract:
Device for exciting a gas comprising:a hollow structure forming a waveguide, made of an electrically conductive material, connected to a microwave generator and including a passage for a hollow dielectric tube adapted for flow of the gas to be excited, said hollow structure further including a wave-concentrating region designed to concentrate microwave radiation produced by the generator onto the tube, during operation of the device, for the purpose of producing a surface wave plasma in the gas, andat least two electromagnetic screening sleeves made of a conductive material, fastened to said hollow structure and extending along the extension of said passage so as to surround said hollow tube, said sleeves extending along the extension of one with respect to the other, on each side of the central part, wherein each sleeve includes an end mounting plate, each mounting plate extending laterally beyond the central part to fix said sleeves to said hollow structure by bolting the mounting plates together,wherein the hollow structure forming the waveguide has a longitudinal general shape and includes a first open end adapted to be connected to said microwave generator, an opposite open end adapted to be provided with a means for forming a short-circuit, and a region of narrowed cross-section which extends between said first open end and said opposite open end and delimits said wave-concentrating region, said region of narrowed cross-section including a central part of constant cross-section equipped with said passage extending between two parts of cross-section which increases linearly towards said ends.