Patent ID: 6696662
Filing Date: 2004-02-24
Classification: H01J,H05H

Abstract:
A method of generating a plasma, the method being carried out using a microwave power source and a rectangular waveguide, the waveguide having an open end capable of receiving microwaves and a closed end, the open end of the waveguide being connected with the microwave power source so as to be capable of receiving microwave power, the microwave power source being capable of providing microwaves at a wavelength lambda, the waveguide having a gas entry port for flowing a gas into the waveguide, the waveguide having a gas exit port for the gas to exit the waveguide, the gas exit port being located at a distance approximately an odd number of quarter wavelengths lambda from the closed end of the waveguide so that the direction of the electric field lines is substantially parallel to or at an angled to the direction of the exit gas flow, the method comprising the steps of:a. providing a gas flow through the waveguide so that the gas exits through the gas exit port; b. providing microwave power to the waveguide so as to create an electric field in the waveguide at the location of the gas exit port; c. extending an electrically conducting member into the waveguide near the gas exit port so as to facilitate igniting the plasma, wherein the conducting member is connected with an electrical ground; and d. coupling sufficient microwave power to the gas to sustain the plasma.