Patent ID: 7858899
Filing Date: 2010-12-28
Classification: H05H

Abstract:
1. A coaxial microwave plasma torch, comprising: a solid cylindrical outside conductor; a cylindrical electric discharge tube inserted into, and fixed to, an axial hole at one end of said electric discharge tube, said axial hole being formed on one end face of said outside conductor, said electric discharge tube having another end protruding from said axial hole; and a coaxial cable for microwave transmission fitted at one end of said coaxial cable to an other end face of said outside conductor from outside, wherein an antenna is electrically connected to an inner conductor of said coaxial cable at said one end of said coaxial cable, a through-hole is formed in said outside conductor in such a way that said through-hole extends in an axial direction from the other end face of said outside conductor toward said axial hole, said antenna is electrically insulated from said outside conductor and extends into said electric discharge tube along the axial direction through said through-hole, an outer conductor of said coaxial cable is electrically connected to said outside conductor, a gas inlet pipeline for supplying gas into said electric discharge tube is provided in said outside conductor, and a cylindrical space is formed between a peripheral surface of said axial hole of said outside conductor and an outer surface of said electric discharge tube, said cylindrical space having a predetermined radial length and extending in the axial direction from a bottom face of said axial hole at an arbitrary length such that said cylindrical space does not reach said one end face of said outside conductor.