Low pressure gas discharges for electric field intensity monitoring in microwave resonant cavities

This paper introduces a new concept in the detection and monitoring of the electric field intensity in high power microwave cavities. It is proposed that the optical emission intensity of a low -pressure gas plasma discharge can be used to describe the strength of the microwave electric field that is powering the plasma. This paper discusses the principles of microwave generated plasmas and demonstrates theoretically using Monte Carlo simulations the emission intensity profile of various gas discharges at varying powers at 2.45GHz and 10GHz. A potential probe design, which uses an optical fibre to couple the discharge emission to a remote photodetector, is also introduced. It is aimed to demonstrate the potential for a new technology that will enable the convenient management of applied microwave power and its spatial distribution.