High power microwave generated plasmas: Experimental and simulated results

Date

2015-05

Journal Title

Journal ISSN

Volume Title

Publisher

Abstract

The power levels and pulse lengths of present high power microwave (HPM) systems operating in a gaseous environment are restricted by the onset of highly conductive plasma at the output window of the transmitting antenna. As the plasma conductivity transitions from an absorptive state to the highly reflective state, the microwave source begins to receive this feedback with potentially damaging and destructive consequences. Furthermore, the surface at which this discharge was located may eventually fail due to a extreme conditions such as heat, electric field stresses, or particle interactions, terminating the operation of such a system.

The goal of this research is to characterize and quantify all phases of the HPM generated plasma from the inception, through the fully developed - highly attenuative state, to the post-breakdown recovery of the system, under various environmental and geometrical conditions. The kinetic theory of gases and gaseous discharge physics are used to develop the pertinent mechanisms associated with rf-driven plasma formation along with predicting and explaining experimentally observed results. Microwave theory was used to design novel waveguide couplers for the study of post-post plasma relaxation. Using gaseous reaction rates available in literature, the dominant plasma recovery pathways are elucidated. Finally, a new plasma confinement structure was designed and built to further use the properties of the induced plasma to benefit the counter-HPM, and microwave engineering communities.

Description

Keywords

High Power Microwaves (HPM), Plasma

Citation