The waveguide surfatron: a high power surface-wave launcher to sustain large-diameter dense plasma columns

Abstract

A novel microwave structure which allows a plasma column to be sustained through the propagation of an electromagnetic surface wave is investigated. This plasma source is analysed in terms of a simple equivalent circuit which correctly predicts the transfer of power from the microwave generator to the plasma as a function of the tuning system of the launcher; it further shows that such a microwave structure is the waveguide equivalent of the surfatron. This device seems a particularly well adapted substitute for the surfatron at 2.45 GHz (or higher frequencies) when there is a need to operate at high (>500 W) microwave power levels or with large (>or=15 mm) tube diameters.